@stdlib/array-bool
v0.1.0
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BooleanArray.
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BooleanArray
Boolean array.
Installation
npm install @stdlib/array-bool
Usage
var BooleanArray = require( '@stdlib/array-bool' );
BooleanArray()
Creates a boolean array.
var arr = new BooleanArray();
// returns <BooleanArray>
BooleanArray( length )
Creates a boolean array having a specified length
.
var arr = new BooleanArray( 10 );
// returns <BooleanArray>
var len = arr.length;
// returns 10
BooleanArray( booleanarray )
Creates a boolean array from another boolean array.
var arr1 = new BooleanArray( [ true, false, false, true ] );
// returns <BooleanArray>
var arr2 = new BooleanArray( arr1 );
// returns <BooleanArray>
var len = arr2.length;
// returns 4
BooleanArray( typedarray )
Creates a boolean array from a typed array.
var Uint8Array = require( '@stdlib/array-uint8' );
var buf = new Uint8Array( [ 1, 0, 0, 1 ] );
// returns <Uint8Array>[ 1, 0, 0, 1 ]
var arr = new BooleanArray( buf );
// returns <BooleanArray>
var len = arr.length;
// returns 4
BooleanArray( obj )
Creates a boolean array from an array-like object or iterable.
// From an array of booleans:
var arr1 = new BooleanArray( [ true, false, false, true ] );
// returns <BooleanArray>
var len = arr1.length;
// returns 4
// From an array containing non-booleans:
var arr2 = new BooleanArray( [ {}, null, '', 4 ] );
len = arr2.length;
// returns 4
BooleanArray( buffer[, byteOffset[, length]] )
Returns a boolean array view of an ArrayBuffer
.
var ArrayBuffer = require( '@stdlib/array-buffer' );
var buf = new ArrayBuffer( 240 );
var arr1 = new BooleanArray( buf );
// returns <BooleanArray>
var len = arr1.length;
// returns 240
var arr2 = new BooleanArray( buf, 8 );
// returns <BooleanArray>
len = arr2.length;
// returns 232
var arr3 = new BooleanArray( buf, 8, 20 );
// returns <BooleanArray>
len = arr3.length;
// returns 20
Properties
BooleanArray.BYTES_PER_ELEMENT
Static property returning the size (in bytes) of each array element.
var nbytes = BooleanArray.BYTES_PER_ELEMENT;
// returns 1
BooleanArray.name
Static property returning the constructor name.
var str = BooleanArray.name;
// returns 'BooleanArray'
BooleanArray.prototype.buffer
Pointer to the underlying data buffer.
var arr = new BooleanArray( 2 );
// returns <BooleanArray>
var buf = arr.buffer;
// returns <ArrayBuffer>
BooleanArray.prototype.byteLength
Size (in bytes) of the array.
var arr = new BooleanArray( 10 );
// returns <BooleanArray>
var nbytes = arr.byteLength;
// returns 10
BooleanArray.prototype.byteOffset
Offset (in bytes) of the array from the start of its underlying ArrayBuffer
.
var ArrayBuffer = require( '@stdlib/array-buffer' );
var arr = new BooleanArray( 10 );
// returns <BooleanArray>
var offset = arr.byteOffset;
// returns 0
var buf = new ArrayBuffer( 240 );
arr = new BooleanArray( buf, 64 );
// returns <BooleanArray>
offset = arr.byteOffset;
// returns 64
BooleanArray.prototype.BYTES_PER_ELEMENT
Size (in bytes) of each array element.
var arr = new BooleanArray( 10 );
// returns <BooleanArray>
var nbytes = arr.BYTES_PER_ELEMENT;
// returns 1
BooleanArray.prototype.length
Number of array elements.
var arr = new BooleanArray( 10 );
// returns <BooleanArray>
var len = arr.length;
// returns 10
Methods
BooleanArray.from( src[, clbk[, thisArg]] )
Creates a new boolean array from an array-like object or an iterable.
var arr = BooleanArray.from( [ true, false ] );
// returns <BooleanArray>
var len = arr.length;
// returns 2
To invoke a function for each src
value, provide a callback function.
function map( v ) {
return !v;
}
// Create a source array:
var src = [ true, false ];
// Create a new boolean array by inverting the source array:
var arr = BooleanArray.from( src, map );
// returns <BooleanArray>
var len = arr.length;
// returns 2
var v = arr.get( 0 );
// returns false
v = arr.get( 1 );
// returns true
A callback function is provided two arguments:
- value: source value.
- index: source index.
To set the callback execution context, provide a thisArg
.
function map( v ) {
this.count += 1;
return !v;
}
// Create a source array:
var src = [ true, false ];
// Define an execution context:
var ctx = {
'count': 0
};
// Create a new boolean array by inverting the source array:
var arr = BooleanArray.from( src, map, ctx );
// returns <BooleanArray>
var len = arr.length;
// returns 2
var n = ctx.count;
// returns 2
BooleanArray.of( element0[, element1[, ...elementN]] )
Creates a new boolean array from a variable number of arguments.
var arr = BooleanArray.of( true, false, false, true );
// returns <BooleanArray>
var len = arr.length;
// returns 4
BooleanArray.prototype.at( i )
Returns an array element located at integer position (index) i
, with support for both nonnegative and negative integer positions.
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var v = arr.at( 0 );
// returns true
v = arr.at( -1 );
// returns true
If provided an out-of-bounds index, the method returns undefined
.
var arr = new BooleanArray( 10 );
var v = arr.at( 100 );
// returns undefined
v = arr.at( -100 );
// returns undefined
BooleanArray.prototype.copyWithin( target, start[, end] )
Copies a sequence of elements within the array starting at start
and ending at end
(non-inclusive) to the position starting at target
.
var arr = new BooleanArray( 4 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( false, 2 );
arr.set( true, 3 );
var v = arr.get( 0 );
// returns true
v = arr.get( 1 );
// returns false
// Copy the last two elements to the first two elements:
arr.copyWithin( 0, 2 );
v = arr.get( 0 );
// returns false
v = arr.get( 1 );
// returns true
By default, end
equals the number of array elements (i.e., one more than the last array index). To limit the sequence length, provide an end
argument.
var arr = new BooleanArray( 4 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( false, 2 );
arr.set( true, 3 );
var v = arr.get( 2 );
// returns false
v = arr.get( 3 );
// returns true
// Copy the first two elements to the last two elements:
arr.copyWithin( 2, 0, 2 );
v = arr.get( 2 );
// returns true
v = arr.get( 3 );
// returns false
When a target
, start
, and/or end
index is negative, the respective index is determined relative to the last array element. The following example achieves the same behavior as the previous example:
var arr = new BooleanArray( 4 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( false, 2 );
arr.set( true, 3 );
var v = arr.get( 2 );
// returns false
v = arr.get( 3 );
// returns true
// Copy the first two elements to the last two elements using negative indices:
arr.copyWithin( -2, -4, -2 );
v = arr.get( 2 );
// returns true
v = arr.get( 3 );
// returns false
BooleanArray.prototype.entries()
Returns an iterator for iterating over array key-value pairs.
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var it = arr.entries();
var v = it.next().value;
// returns [ 0, true ]
v = it.next().value;
// returns [ 1, false ]
v = it.next().value;
// returns [ 2, true ]
var bool = it.next().done;
// returns true
The returned iterator protocol-compliant object has the following properties:
- next: function which returns an iterator protocol-compliant object containing the next iterated value (if one exists) assigned to a
value
property and adone
property having aboolean
value indicating whether the iterator is finished. - return: function which closes an iterator and returns a single (optional) argument in an iterator protocol-compliant object.
BooleanArray.prototype.every( predicate[, thisArg] )
Returns a boolean indicating whether all elements pass a test.
function predicate( v ) {
return v === true;
}
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( true, 1 );
arr.set( true, 2 );
var bool = arr.every( predicate );
// returns true
The predicate
function is provided three arguments:
- value: current array element.
- index: current array element index.
- arr: the array on which this method was called.
To set the function execution context, provide a thisArg
.
function predicate( v ) {
this.count += 1;
return v === true;
}
var arr = new BooleanArray( 3 );
var context = {
'count': 0
};
arr.set( true, 0 );
arr.set( true, 1 );
arr.set( true, 2 );
var bool = arr.every( predicate, context );
// returns true
var count = context.count;
// returns 3
BooleanArray.prototype.fill( value[, start[, end]] )
Returns a modified typed array filled with a fill value.
var arr = new BooleanArray( 3 );
// Set all elements to the same value:
arr.fill( true );
var v = arr.get( 0 );
// returns true
v = arr.get( 1 );
// returns true
v = arr.get( 2 );
// returns true
// Fill all elements starting from the second element:
arr.fill( false, 1 );
v = arr.get( 1 );
// returns false
v = arr.get( 2 );
// returns false
// Fill all elements from first element until the second-to-last element:
arr.fill( false, 0, 2 );
v = arr.get( 0 );
// returns false
v = arr.get( 1 );
// returns false
When a start
and/or end
index is negative, the respective index is determined relative to the last array element.
var arr = new BooleanArray( 3 );
// Set all array elements, except the last element, to the same value:
arr.fill( true, 0, -1 );
var v = arr.get( 0 );
// returns true
v = arr.get( 2 );
// returns false
BooleanArray.prototype.filter( predicate[, thisArg] )
Returns a new array containing the elements of an array which pass a test implemented by a predicate function.
function predicate( v ) {
return ( v === true );
}
var arr = new BooleanArray( 3 );
// Set the first three elements:
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var out = arr.filter( predicate );
// returns <BooleanArray>
var len = out.length;
// returns 2
var v = out.get( 0 );
// returns true
v = out.get( 1 );
// return true
The predicate
function is provided three arguments:
- value: current array element.
- index: current array element index.
- arr: the array on which this method was called.
To set the function execution context, provide a thisArg
.
function predicate( v, i ) {
this.count += 1;
return ( v === true );
}
var arr = new BooleanArray( 3 );
var context = {
'count': 0
};
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var out = arr.filter( predicate, context );
// returns <BooleanArray>
var len = out.length;
// returns 2
var count = context.count;
// returns 3
BooleanArray.prototype.find( predicate[, thisArg] )
Returns the first element in an array for which a predicate function returns a truthy value.
function predicate( v ) {
return v === true;
}
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var v = arr.find( predicate );
// returns true
The predicate
function is provided three arguments:
- value: current array element.
- index: current array element index.
- arr: the array on which this method was called.
To set the function execution context, provide a thisArg
.
function predicate( v ) {
this.count += 1;
return ( v === true );
}
var arr = new BooleanArray( 3 );
var context = {
'count': 0
};
arr.set( false, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var z = arr.find( predicate, context );
// returns true
var count = context.count;
// returns 3
BooleanArray.prototype.findIndex( predicate[, thisArg] )
Returns the index of the first element in an array for which a predicate function returns a truthy value.
function predicate( v ) {
return v === true;
}
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var v = arr.findIndex( predicate );
// returns 0
The predicate
function is provided three arguments:
- value: current array element.
- index: current array element index.
- arr: the array on which this method was called.
To set the function execution context, provide a thisArg
.
function predicate( v ) {
this.count += 1;
return ( v === true );
}
var arr = new BooleanArray( 3 );
var context = {
'count': 0
};
arr.set( false, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var z = arr.findIndex( predicate, context );
// returns 2
var count = context.count;
// returns 3
BooleanArray.prototype.findLast( predicate[, thisArg] )
Returns the last element in an array for which a predicate function returns a truthy value.
function predicate( v ) {
return v === true;
}
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var v = arr.findLast( predicate );
// returns true
The predicate
function is provided three arguments:
- value: current array element.
- index: current array element index.
- arr: the array on which this method was called.
To set the function execution context, provide a thisArg
.
function predicate( v ) {
this.count += 1;
return ( v === true );
}
var arr = new BooleanArray( 3 );
var context = {
'count': 0
};
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( false, 2 );
var z = arr.findLast( predicate, context );
// returns true
var count = context.count;
// returns 3
BooleanArray.prototype.findLastIndex( predicate[, thisArg] )
Returns the index of the last element in an array for which a predicate function returns a truthy value.
function predicate( v ) {
return v === true;
}
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var v = arr.findLastIndex( predicate );
// returns 2
The predicate
function is provided three arguments:
- value: current array element.
- index: current array element index.
- arr: the array on which this method was called.
To set the function execution context, provide a thisArg
.
function predicate( v ) {
this.count += 1;
return ( v === true );
}
var arr = new BooleanArray( 3 );
var context = {
'count': 0
};
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( false, 2 );
var z = arr.findLastIndex( predicate, context );
// returns 0
var count = context.count;
// returns 3
BooleanArray.prototype.forEach( callbackFn[, thisArg] )
Invokes a function once for each array element.
function log( v, i ) {
console.log( '%s: %s', i, v.toString() );
}
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
arr.forEach( log );
/* =>
0: true
1: false
2: true
*/
The invoked function is provided three arguments:
- value: current array element.
- index: current array element index.
- arr: the array on which this method was called.
To set the function execution context, provide a thisArg
.
function fcn( v, i ) {
this.count += 1;
console.log( '%s: %s', i, v.toString() );
}
var arr = new BooleanArray( 3 );
var context = {
'count': 0
};
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
arr.forEach( fcn, context );
/* =>
0: 1 + 1i
1: 2 + 2i
2: 3 + 3i
*/
var count = context.count;
// returns 3
BooleanArray.prototype.get( i )
Returns an array element located at a nonnegative integer position (index) i
.
var arr = new BooleanArray( 10 );
// Set the first element:
arr.set( true, 0 );
// Get the first element:
var v = arr.get( 0 );
// returns true
If provided an out-of-bounds index, the method returns undefined
.
var arr = new BooleanArray( 10 );
var v = arr.get( 100 );
// returns undefined
BooleanArray.prototype.includes( searchElement[, fromIndex] )
Returns a boolean indicating whether an array includes a provided value.
var arr = new BooleanArray( 5 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
arr.set( true, 3 );
arr.set( true, 4 );
var bool = arr.includes( true );
// returns true
bool = arr.includes( false, 2 );
// returns false
BooleanArray.prototype.indexOf( searchElement[, fromIndex] )
Returns the first index at which a given element can be found.
var arr = new BooleanArray( 5 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
arr.set( true, 3 );
arr.set( true, 4 );
var idx = arr.indexOf( true );
// returns 0
idx = arr.indexOf( false, 1 );
// returns 1
idx = arr.indexOf( true, -3 );
// returns 2
If searchElement
is not present in the array, the method returns -1
.
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( true, 1 );
arr.set( true, 2 );
var idx = arr.indexOf( false );
// returns -1
BooleanArray.prototype.join( [separator] )
Returns a new string by concatenating all array elements.
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var str = arr.join();
// returns 'true,false,true'
By default, the method separates serialized array elements with a comma. To use an alternative separator, provide a separator
string.
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var str = arr.join( '|' );
// returns 'true|false|true'
BooleanArray.prototype.keys()
Returns an iterator for iterating over each index key in a typed array.
var arr = new BooleanArray( 2 );
arr.set( true, 0 );
arr.set( false, 1 );
var iter = arr.keys();
var v = iter.next().value;
// returns 0
v = iter.next().value;
// returns 1
var bool = iter.next().done;
// returns true
The returned iterator protocol-compliant object has the following properties:
- next: function which returns an iterator protocol-compliant object containing the next iterated value (if one exists) assigned to a
value
property and adone
property having aboolean
value indicating whether the iterator is finished. - return: function which closes an iterator and returns a single (optional) argument in an iterator protocol-compliant object.
BooleanArray.prototype.lastIndexOf( searchElement[, fromIndex] )
Returns the last index at which a given element can be found.
var arr = new BooleanArray( 5 );
arr.set( true, 0 );
arr.set( true, 1 );
arr.set( true, 2 );
arr.set( false, 3 );
arr.set( true, 4 );
var idx = arr.lastIndexOf( true );
// returns 4
idx = arr.lastIndexOf( false, 3 );
// returns 3
idx = arr.lastIndexOf( true, -3 );
// returns 2
If searchElement
is not present in the array, the method returns -1
.
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( true, 1 );
arr.set( true, 2 );
var idx = arr.lastIndexOf( false );
// returns -1
BooleanArray.prototype.map( callbackFn[, thisArg] )
Returns a new array with each element being the result of a provided callback function.
function invert( v ) {
return !v;
}
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var out = arr.map( invert );
// returns <BooleanArray>
var z = out.get( 0 );
// returns false
z = out.get( 1 );
// returns true
z = out.get( 2 );
// returns false
The callback function is provided three arguments:
- value: current array element.
- index: current array element index.
- arr: the array on which this method was called.
To set the function execution context, provide a thisArg
.
function invert( v, i ) {
this.count += i;
return !v;
}
var arr = new BooleanArray( 3 );
var context = {
'count': 0
};
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var out = arr.map( invert, context );
// returns <BooleanArray>
var count = context.count;
// returns 3;
BooleanArray.prototype.reduce( reducerFn[, initialValue] )
Applies a provided callback function to each element of the array, in order, passing in the return value from the calculation on the preceding element and returning the accumulated result upon completion.
function reducer( acc, v ) {
return ( acc && v );
}
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var out = arr.reduce( reducer );
// returns false
The reducer function is provided four arguments:
- acc: accumulated result.
- value: current array element.
- index: current array element index.
- arr: the array on which this method was called.
By default, the function initializes the accumulated result to the first element in the array and passes the second array element as value
during the first invocation of the provided callback. To begin accumulation from a different starting value and pass in the first array element as value
during the first invocation of the provided callback, provide an initialValue
argument.
function reducer( acc, v ) {
if ( v ) {
return acc + 1;
}
return acc;
}
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var out = arr.reduce( reducer, 0 );
// returns 2
BooleanArray.prototype.reduceRight( reducerFn[, initialValue] )
Applies a provided callback function to each element of the array, in reverse order, passing in the return value from the calculation on the following element and returning the accumulated result upon completion.
function reducer( acc, v ) {
return ( acc && v );
}
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var out = arr.reduceRight( reducer );
// returns false
The reducer function is provided four arguments:
- acc: accumulated result.
- value: current array element.
- index: current array element index.
- arr: the array on which this method was called.
By default, the function initializes the accumulated result to the last element in the array and passes the second-last array element as value
during the first invocation of the provided callback. To begin accumulation from a different starting value and pass in the last array element as value
during the first invocation of the provided callback, provide an initialValue
argument.
function reducer( acc, v ) {
if ( v ) {
return acc + 1;
}
return acc;
}
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var out = arr.reduceRight( reducer, 0 );
// returns 2
BooleanArray.prototype.reverse()
Reverses an array in-place.
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( false, 2 );
var out = arr.reverse();
// returns <BooleanArray>
var v = out.get( 0 );
// returns false
v = out.get( 1 );
// returns false
v = out.get( 2 );
// returns true
BooleanArray.prototype.set( v[, i] )
Sets one or more array elements.
var arr = new BooleanArray( 10 );
// Get the first element:
var v = arr.get( 0 );
// returns false
// Set the first element:
arr.set( true );
// Get the first element:
v = arr.get( 0 );
// returns true
By default, the method sets array elements starting at position (index) i = 0
. To set elements starting elsewhere in the array, provide an index argument i
.
var arr = new BooleanArray( 10 );
// Get the fifth element:
var v = arr.get( 4 );
// returns false
// Set the fifth element:
arr.set( true, 4 );
// Get the fifth element:
v = arr.get( 4 );
// returns true
In addition to providing a single value, to set one or more array elements, provide an array-like object containing truthy and falsy values
var arr = new BooleanArray( 10 );
// Define an array of values:
var buf = [ '', 1, null ];
// Set the fifth, sixth, and seventh elements:
arr.set( buf, 4 );
// Get the sixth element:
var v = arr.get( 5 );
// returns true
A few notes:
- If
i
is out-of-bounds, the method throws an error. - If a target array cannot accommodate all values (i.e., the length of source array plus
i
exceeds the target array length), the method throws an error. - If provided a typed array which shares an
ArrayBuffer
with the target array, the method will intelligently copy the source range to the destination range.
BooleanArray.prototype.slice( [start[, end]] )
Copies a portion of a typed array to a new typed array.
var arr = new BooleanArray( 5 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
arr.set( false, 3 );
arr.set( true, 4 );
var out = arr.slice();
// returns <BooleanArray>
var len = out.length;
// returns 5
var bool = out.get( 0 );
// returns true
bool = out.get( len-1 );
// returns true
By default, the method returns a typed array beginning with the first array element. To specify an alternative array index at which to begin, provide a start
index (inclusive).
var arr = new BooleanArray( 5 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
arr.set( false, 3 );
arr.set( true, 4 );
var out = arr.slice( 1 );
// returns <BooleanArray>
var len = out.length;
// returns 4
var bool = out.get( 0 );
// returns false
bool = out.get( len-1 );
// returns true
By default, the method returns a typed array which includes all array elements after start
. To limit the number of array elements after start
, provide an end
index (exclusive).
var arr = new BooleanArray( 5 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
arr.set( false, 3 );
arr.set( true, 4 );
var out = arr.slice( 1, -2 );
// returns <BooleanArray>
var len = out.length;
// returns 2
var bool = out.get( 0 );
// returns false
bool = out.get( len-1 );
// returns true
BooleanArray.prototype.some( predicate[, thisArg] )
Returns a boolean indicating whether at least one element passes a test.
function predicate( v ) {
return v === true;
}
var arr = new BooleanArray( 3 );
arr.set( false, 0 );
arr.set( true, 1 );
arr.set( false, 2 );
var bool = arr.some( predicate );
// returns true
The predicate
function is provided three arguments:
- value: current array element.
- index: current array element index.
- arr: the array on which this method was called.
To set the function execution context, provide a thisArg
.
function predicate( v ) {
this.count += 1;
return v === true;
}
var arr = new BooleanArray( 3 );
var context = {
'count': 0
};
arr.set( false, 0 );
arr.set( true, 1 );
arr.set( false, 2 );
var bool = arr.some( predicate, context );
// returns true
var count = context.count;
// returns 2
BooleanArray.prototype.sort( [compareFcn] )
Sorts an array in-place.
function compare( a, b ) {
if ( a === false ) {
if ( b === false ) {
return 0;
}
return 1;
}
if ( b === true ) {
return 0;
}
return -1;
}
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
arr.sort( compare );
var v = arr.get( 0 );
// returns true
v = arr.get( 1 );
// returns true
v = arr.get( 2 );
// returns false
The compareFcn
determines the order of the elements. The function is called with the following arguments:
- a: the first boolean value for comparison.
- b: the second boolean value for comparison.
The function should return a number where:
- a negative value indicates that
a
should come beforeb
. - a positive value indicates that
a
should come afterb
. - zero or
NaN
indicates thata
andb
are considered equal.
BooleanArray.prototype.subarray( [begin[, end]] )
Creates a new typed array view over the same underlying ArrayBuffer
and with the same underlying data type as the host array.
var arr = new BooleanArray( 5 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
arr.set( false, 3 );
arr.set( true, 4 );
var subarr = arr.subarray();
// returns <BooleanArray>
var len = subarr.length;
// returns 5
var bool = subarr.get( 0 );
// returns true
bool = subarr.get( len-1 );
// returns true
By default, the method creates a typed array view beginning with the first array element. To specify an alternative array index at which to begin, provide a begin
index (inclusive).
var arr = new BooleanArray( 5 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
arr.set( false, 3 );
arr.set( true, 4 );
var subarr = arr.subarray( 1 );
// returns <BooleanArray>
var len = subarr.length;
// returns 4
var bool = subarr.get( 0 );
// returns false
bool = subarr.get( len-1 );
// returns true
By default, the method creates a typed array view which includes all array elements after begin
. To limit the number of array elements after begin
, provide an end
index (exclusive).
var arr = new BooleanArray( 5 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
arr.set( false, 3 );
arr.set( true, 4 );
var subarr = arr.subarray( 1, -2 );
// returns <BooleanArray>
var len = subarr.length;
// returns 2
var bool = subarr.get( 0 );
// returns false
bool = subarr.get( len-1 );
// returns true
BooleanArray.prototype.toLocaleString( [locales[, options]] )
Serializes an array as a locale-specific string.
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var str = arr.toLocaleString();
// returns 'true,false,true'
The method supports the following arguments:
- locales: a string with a BCP 47 language tag or an array of such strings.
- options: configuration properties.
BooleanArray.prototype.toReversed()
Returns a new typed array containing the elements in reversed order.
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( false, 2 );
var out = arr.toReversed();
// returns <BooleanArray>
var v = out.get( 0 );
// returns false
v = out.get( 1 );
// returns false
v = out.get( 2 );
// returns true
BooleanArray.prototype.toSorted( [compareFcn] )
Returns a new typed array containing the elements in sorted order.
function compare( a, b ) {
if ( a === false ) {
if ( b === false ) {
return 0;
}
return 1;
}
if ( b === true ) {
return 0;
}
return -1;
}
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var out = arr.sort( compare );
// returns <BooleanArray>
var v = out.get( 0 );
// returns true
v = out.get( 1 );
// returns true
v = out.get( 2 );
// returns false
The compareFcn
determines the order of the elements. The function is called with the following arguments:
- a: the first boolean value for comparison.
- b: the second boolean value for comparison.
The function should return a number where:
- a negative value indicates that
a
should come beforeb
. - a positive value indicates that
a
should come afterb
. - zero or
NaN
indicates thata
andb
are considered equal.
BooleanArray.prototype.toString()
Serializes an array as a string.
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 2 );
var str = arr.toString();
// returns 'true,false,true'
BooleanArray.prototype.values()
Returns an iterator for iterating over each value in a typed array.
var arr = new BooleanArray( 2 );
arr.set( true, 0 );
arr.set( false, 1 );
var iter = arr.values();
var v = iter.next().value;
// returns true
v = iter.next().value;
// returns false
var bool = iter.next().done;
// returns true
The returned iterator protocol-compliant object has the following properties:
- next: function which returns an iterator protocol-compliant object containing the next iterated value (if one exists) assigned to a
value
property and adone
property having aboolean
value indicating whether the iterator is finished. - return: function which closes an iterator and returns a single (optional) argument in an iterator protocol-compliant object.
BooleanArray.prototype.with( index, value )
Returns a new typed array with the element at a provided index replaced with a provided value.
var arr = new BooleanArray( 3 );
arr.set( true, 0 );
arr.set( false, 1 );
arr.set( true, 1 );
var out = arr.with( 0, false );
// returns <BooleanArray>
var v = out.get( 0 );
// returns false
Notes
While a
BooleanArray
strives to maintain (but does not guarantee) consistency with typed arrays, significant deviations from ECMAScript-defined typed array behavior are as follows:- The constructor does not require the
new
operator. - Accessing array elements using bracket syntax (e.g.,
X[i]
) is not supported. Instead, one must use the.get()
method.
- The constructor does not require the
Examples
var Uint8Array = require( '@stdlib/array-uint8' );
var logEach = require( '@stdlib/console-log-each' );
var BooleanArray = require( '@stdlib/array-bool' );
// Create a boolean array by specifying a length:
var out = new BooleanArray( 3 );
logEach( '%s', out );
// Create a boolean array from an array of booleans:
var arr = [ true, false, true ];
out = new BooleanArray( arr );
logEach( '%s', out );
// Create a boolean array from an array buffer:
arr = new Uint8Array( [ 1, 0, 1, 1, 0, 1 ] );
out = new BooleanArray( arr.buffer );
logEach( '%s', out );
// Create a boolean array from an array buffer view:
arr = new Uint8Array( [ 1, 0, 1, 1, 0, 1 ] );
out = new BooleanArray( arr.buffer, 1, 2 );
logEach( '%s', out );
console.log( '%s', false );
Notice
This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.
For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.
Community
License
See LICENSE.
Copyright
Copyright © 2016-2024. The Stdlib Authors.