@stdlib/utils-every-own-by NPM

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>

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.