npm package: @stdlib/object-every-own-by
Description: Test whether all own properties of an object pass a test implemented by a predicate function.
Author: The Stdlib Authors
Latest version: 0.1.1

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  <summary>
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# everyOwnBy

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

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

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

</section>

<!-- /.intro -->

<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/object-every-own-by
```

</section>

<section class="usage">

## Usage

```javascript
var everyOwnBy = require( '@stdlib/object-every-own-by' );
```

#### everyOwnBy( object, predicate\[, thisArg ] )

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

```javascript
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`.

```javascript
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`.

```javascript
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
```

</section>

<!-- /.usage -->

<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

## Notes

-   If the 1st argument is not an [`object`][mdn-object] or the second argument is not a function, the function throws a Type Error.

-   If provided an empty object, the function returns `true`.

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

</section>

<!-- /.notes -->

<!-- Package usage examples. -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var randu = require( '@stdlib/random-base-randu' );
var everyOwnBy = require( '@stdlib/object-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>
```

</section>

<!-- /.examples -->

<!-- Section to include cited references. If references are included, add a horizontal rule *before* the section. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="references">

</section>

<!-- /.references -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/object-any-own-by`][@stdlib/object/any-own-by]</span><span class="delimiter">: </span><span class="description">test whether whether any 'own' property of a provided object satisfies a predicate function.</span>
-   <span class="package-name">[`@stdlib/object-every-in-by`][@stdlib/object/every-in-by]</span><span class="delimiter">: </span><span class="description">test whether all properties (own and inherited) of an object pass a test implemented by a predicate function.</span>
-   <span class="package-name">[`@stdlib/object-none-own-by`][@stdlib/object/none-own-by]</span><span class="delimiter">: </span><span class="description">tests whether every own property of an object fails a test implemented by a predicate function.</span>
-   <span class="package-name">[`@stdlib/object-some-own-by`][@stdlib/object/some-own-by]</span><span class="delimiter">: </span><span class="description">test whether some `own` properties of a provided object satisfy a predicate function for at least `n` properties.</span>
-   <span class="package-name">[`@stdlib/utils-every-by`][@stdlib/utils/every-by]</span><span class="delimiter">: </span><span class="description">test whether all elements in a collection pass a test implemented by a predicate function.</span>

</section>

<!-- /.related -->

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<section class="main-repo" >

* * *

## Notice

This package is part of [stdlib][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][stdlib], see the main project [repository][stdlib].

#### Community

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

</section>

<!-- /.stdlib -->

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[npm-url]: https://npmjs.org/package/@stdlib/object-every-own-by

[test-image]: https://github.com/stdlib-js/object-every-own-by/actions/workflows/test.yml/badge.svg?branch=v0.1.1
[test-url]: https://github.com/stdlib-js/object-every-own-by/actions/workflows/test.yml?query=branch:v0.1.1

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/object-every-own-by/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/object-every-own-by?branch=main

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[stdlib]: https://github.com/stdlib-js/stdlib

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[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules

[deno-url]: https://github.com/stdlib-js/object-every-own-by/tree/deno
[deno-readme]: https://github.com/stdlib-js/object-every-own-by/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/object-every-own-by/tree/umd
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[esm-url]: https://github.com/stdlib-js/object-every-own-by/tree/esm
[esm-readme]: https://github.com/stdlib-js/object-every-own-by/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/object-every-own-by/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/object-every-own-by/main/LICENSE

[mdn-object]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object

<!-- <related-links> -->

[@stdlib/object/any-own-by]: https://www.npmjs.com/package/@stdlib/object-any-own-by

[@stdlib/object/every-in-by]: https://www.npmjs.com/package/@stdlib/object-every-in-by

[@stdlib/object/none-own-by]: https://www.npmjs.com/package/@stdlib/object-none-own-by

[@stdlib/object/some-own-by]: https://www.npmjs.com/package/@stdlib/object-some-own-by

[@stdlib/utils/every-by]: https://www.npmjs.com/package/@stdlib/utils-every-by

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