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countSameValue

Count the number of elements in an array that are equal to a specified value.

Installation

npm install @stdlib/array-base-count-same-value

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 countSameValue = require( '@stdlib/array-base-count-same-value' );

countSameValue( x, value )

Counts the number of elements in an array that are equal to a specified value.

var x = [ 0, 1, 0, 1, 2 ];

var out = countSameValue( x, 1 );
// returns 2

In contrast to an implementation using the strict equality operator ===, the function distinguishes between +0 and -0 and treats NaNs as the same value.

var x = [ NaN, NaN, NaN ];

var out = countSameValue( x, NaN );
// returns 3

Notes

• The function uses the SameValue Algorithm as specified in ECMAScript 5.

Examples

var bernoulli = require( '@stdlib/random-array-bernoulli' );
var countSameValue = require( '@stdlib/array-base-count-same-value' );

var x = bernoulli( 10, 0.5, {
    'dtype': 'generic'
});
console.log( x );

var n = countSameValue( x, 1 );
console.log( n );

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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.