@stdlib/utils-any-in-by v0.1.0

anyInBy

Test whether at least one property in an object passes a test implemented by a predicate function.

Installation

npm install @stdlib/utils-any-in-by

Usage

var anyInBy = require( '@stdlib/utils-any-in-by' );

anyInBy( object, predicate[, thisArg ] )

Tests whether at least one property in an object passes a test implemented by a predicate function.

function isNegative( value ) {
    return ( value < 0 );
}

var obj = {
    'a': 1,
    'b': 2,
    'c': -1
};

var bool = anyInBy( obj, isNegative );
// returns true

If a predicate function returns a truthy value, the function immediately returns true.

function isPositive( value ) {
    if ( value < 0 ) {
        throw new Error( 'should never reach this line' );
    }
    return ( value > 0 );
}

var obj = {
    'a': 1,
    'b': -2,
    'c': 3
};

var bool = anyInBy( obj, isPositive );
// returns true

The invoked function is provided three arguments:

• value: property value
• key: property key
• object: input object

To set the function execution context, provide a thisArg.

function sum( value ) {
    this.sum += value;
    this.count += 1;
    return ( value < 0 );
}

var obj = {
    'a': 1,
    'b': 2,
    'c': 3,
    'd': -4
};

var context = {
    'sum': 0,
    'count': 0
};

var bool = anyInBy( obj, sum, context );
// returns true

var mean = context.sum / context.count;
// returns 0.5

Notes

• The obj object may contain own properties as well as inherited properties from its prototype chain.

• If provided an empty object, the function returns false.

  function alwaysTrue() {
      return true;
  }
  var bool = anyInBy( {}, alwaysTrue );
  // returns false

Examples

var randu = require( '@stdlib/random-base-randu' );
var anyInBy = require( '@stdlib/utils-any-in-by' );

function threshold( value ) {
    return ( value > 0.95 );
}

var bool;
var obj = {};
var i;

for ( i = 0; i < 100; i++ ) {
    obj[i] = randu();
}

bool = anyInBy( obj, threshold );
// returns <boolean>

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 © 2016-2024. The Stdlib Authors.