cueveryBy

Cumulatively test whether every array element in a provided array passes a test implemented by a predicate function.

Installation

npm install @stdlib/array-base-cuevery-by

Usage

var cueveryBy = require( '@stdlib/array-base-cuevery-by' );

cueveryBy( x, predicate[, thisArg ] )

Cumulatively tests whether every array element in a provided array passes a test implemented by a predicate function.

function fcn( value) {
    return ( value > 0 );
}

var x = [ 1, 1, 0, 0, 0 ];

var y = cueveryBy( x, fcn );
// returns [ true, true, false, false, false ]

The invoked predicate function is provided three arguments:

• value: collection element.
• index: collection index.
• collection: input collection.

To set the function execution context, provide a thisArg.

function fcn( v ) {
    this.count += 1;
    return ( v > 0 );
}

var x = [ 1, 1, 0, 0, 0 ];

var context = {
    'count': 0
};

var bool = cueveryBy( x, fcn, context );
// returns [ true, true, false, false, false ]

var count = context.count;
// returns 3

cueveryBy.assign( x, out, stride, offset, predicate[, thisArg ] )

Cumulatively tests whether every array element in a provided array passes a test implemented by a predicate function and assigns the results to a provided output array.

function fcn( v ) {
    return ( v > 0 );
}

var x = [ 1, 1, 0, 0, 0 ];
var y = [ false, null, false, null, false, null, false, null, false, null ];

var out = cueveryBy.assign( x, y, 2, 0, fcn );
// returns [ true, null, true, null, false, null, false, null, false, null ]

var bool = ( out === y );
// returns true

Examples

var bernoulli = require( '@stdlib/random-array-bernoulli' );
var cueveryBy = require( '@stdlib/array-base-cuevery-by' );

function fcn( value ) {
    return ( value > 0 );
}

// Create an array of random values:
var x = bernoulli( 10, 0.8 );
console.log( x );

// Cumulatively tests whether every array element passes a test:
var y = cueveryBy( x, fcn );
console.log( y );

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 © 2016-2026. The Stdlib Authors.