About stdlib...
We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.
The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.
When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.
To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!
Test whether all elements in an array pass a test implemented by a predicate function.
npm install @stdlib/array-base-every-byAlternatively,
- To load the package in a website via a
scripttag without installation and bundlers, use the ES Module available on theesmbranch (see README). - If you are using Deno, visit the
denobranch (see README for usage intructions). - For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the
umdbranch (see README).
The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.
To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.
var everyBy = require( '@stdlib/array-base-every-by' );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 trueIf 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 falseThe 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-
If provided an array-like object having an
everymethod, 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
everymethod, 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 skipundefinedelements. -
If provided an empty array, the function returns
true.
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>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.
See LICENSE.
Copyright © 2016-2025. The Stdlib Authors.
