@stdlib/array-base-every-by
v0.2.2
Published
Test whether all elements in an array pass a test implemented by a predicate function.
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everyBy
Test whether all elements in an array pass a test implemented by a predicate function.
Installation
npm install @stdlib/array-base-every-by
Usage
var everyBy = require( '@stdlib/array-base-every-by' );
everyBy( x, predicate[, thisArg] )
Tests whether all elements in an array pass a test implemented by a predicate
function.
function isPositive( value ) {
return ( value > 0 );
}
var x = [ 1, 2, 3, 4 ];
var bool = everyBy( x, isPositive );
// returns true
If a predicate
function returns a non-truthy value, the function immediately returns false
.
function isPositive( value ) {
return ( value > 0 );
}
var x = [ 1, -2, 3, 4 ];
var bool = everyBy( x, isPositive );
// returns false
The predicate
function is provided three arguments:
- value: current array element.
- index: current array element index.
- arr: input array.
To set the predicate
function execution context, provide a thisArg
.
function predicate( value ) {
this.count += 1;
return ( value > 0 );
}
var x = [ 1, 2, -3, 4 ];
var context = {
'count': 0
};
var bool = everyBy( x, predicate, context );
// returns false
var cnt = context.count;
// returns 3
Notes
If provided an array-like object having an
every
method, the function defers execution to that method and assumes that the method API has the following signature:x.every( predicate, thisArg )
If provided an array-like object without an
every
method, the function performs a linear scan and returns immediately upon encountering a non-truthy return value. UnlikeArray.prototype.every
, when performing a linear scan, the function does not skipundefined
elements.If provided an empty array, the function returns
true
.
Examples
var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var isPositiveInteger = require( '@stdlib/assert-is-positive-integer' ).isPrimitive;
var naryFunction = require( '@stdlib/utils-nary-function' );
var everyBy = require( '@stdlib/array-base-every-by' );
var x = discreteUniform( 10, 0, 10, {
'dtype': 'int32'
});
// returns <Int32Array>
var out = everyBy( x, naryFunction( isPositiveInteger, 1 ) );
// returns <boolean>
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.