while

Invoke a function while a test condition is true.

Installation

npm install @stdlib/utils-while

Usage

var whilst = require( '@stdlib/utils-while' );

whilst( predicate, fcn[, thisArg ] )

Invokes a function until a predicate function returns false.

function predicate( i ) {
    return ( i < 5 );
}

function beep( i ) {
    console.log( 'boop: %d', i );
}

whilst( predicate, beep );
/* =>
    boop: 0
    boop: 1
    boop: 2
    boop: 3
    boop: 4
*/

Both the predicate function and the function to invoke are provided a single argument:

• i: iteration number (starting from zero)

To set the function execution context for the invoked function, provide a thisArg.

function predicate( i ) {
    return ( i < 5 );
}

function count() {
    this.count += 1;
}

var context = {
    'count': 0
};

whilst( predicate, count, context );

console.log( context.count );
// => 5

Examples

var randu = require( '@stdlib/random-base-randu' );
var whilst = require( '@stdlib/utils-while' );

function predicate() {
    return ( randu() > 0.05 );
}

function log( i ) {
    console.log( i );
}

whilst( predicate, log );

See Also

• @stdlib/utils-do-until: invoke a function until a test condition is true.
• @stdlib/utils-do-while: invoke a function while a test condition is true.
• @stdlib/utils-until: invoke a function until a test condition is true.
• @stdlib/utils-async/while: invoke a function while a test condition is true.
• @stdlib/utils-while-each: while a test condition is true, invoke a function for each element in a collection.

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.