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none

Test whether all elements in a collection are falsy.

Installation

npm install @stdlib/utils-none

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (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.

Usage

var none = require( '@stdlib/utils-none' );

none( collection )

Tests whether all elements in a collection are falsy.

var arr = [ 0, 0, 0, 0, 0 ];

var bool = none( arr );
// returns true

If provided an empty collection, the function returns true.

var bool = none( [] );
// returns true

Notes

• A collection may be either an Array, Typed Array, or an array-like Object (excluding strings and functions).
• The function does not skip undefined elements and is thus not optimized for sparse collections.

Examples

var randu = require( '@stdlib/random-base-randu' );
var none = require( '@stdlib/utils-none' );

var bool;
var arr;
var i;

arr = new Array( 100 );
for ( i = 0; i < arr.length; i++ ) {
    arr[ i ] = ( randu() > 0.95 );
}

bool = none( arr );
// returns <boolean>

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See Also

• @stdlib/utils-any: test whether at least one element in a collection is truthy.
• @stdlib/utils-every: test whether all elements in a collection are truthy.
• @stdlib/utils-for-each: invoke a function for each element in a collection.
• @stdlib/utils-none-by: test whether all elements in a collection fail a test implemented by a predicate function.
• @stdlib/utils-some: test whether a collection contains at least n elements which are truthy.

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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

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License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.