@stdlib/utils-every-own-by

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everyOwnBy

Test whether all own propertes of an object pass a test implemented by a predicate function.

Installation

npm install @stdlib/utils-every-own-by

Usage

var everyOwnBy = require( '@stdlib/utils-every-own-by' );

everyOwnBy( object, predicate[, thisArg ] )

Tests whether all own properties of an object pass a test implemented by a predicate function.

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

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

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

If a predicate function returns a non-truthy value, the function immediately returns false.

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

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

var bool = everyOwnBy( obj, isPositive );
// returns false

The invoked function is provided three arguments:

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

To set the function execution context, provide a thisArg.

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

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

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

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

var mean = context.sum / context.count;
// returns 2

Notes

• If the 1st argument is not an object or the second argument is not a fuction , the function throws a Type Error.

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

  function untrue() {
      return false;
  }
  var bool = everyOwnBy( {}, untrue );
  // returns true

Examples

var randu = require( '@stdlib/random-base-randu' );
var everyOwnBy = require( '@stdlib/utils-every-own-by' );

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

var obj = {};
var i;

// Populate object with random values
for ( i = 0; i < 100; i++ ) {
    obj[ 'prop_' + i ] = randu();
}

var bool = everyOwnBy( obj, isPositive );
// returns <boolean>

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See Also

• @stdlib/utils-any-own-by: test whether whether any 'own' property of a provided object satisfies a predicate function.
• @stdlib/utils-every-in-by: test whether all properties (own and inherited) of an object pass a test implemented by a predicate function.
• @stdlib/utils-none-own-by: tests whether every own property of an object fails a test implemented by a predicate function.
• @stdlib/utils-some-own-by: test whether some own properties of a provided object satisfy a predicate function for at least n properties.
• @stdlib/utils-every-by: test whether all elements in a collection pass a test implemented by a predicate function.

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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.