@stdlib/utils-do-while NPM

doWhile

Invoke a function while a test condition is true.

Installation

npm install @stdlib/utils-do-while

Usage

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

doWhile( fcn, predicate[, thisArg ] )

Invokes a function until a predicate function returns false. Note that the predicate function is evaluated after executing fcn; thus, fcn always executes at least once.

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

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

doWhile( beep, predicate );
/* =>
    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
};

doWhile( count, predicate, context );

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

Examples

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

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

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

doWhile( log, predicate );

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.