Test whether an object contains a nested key path, either own or inherited.
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> Test whether an object contains a nested key path, either own or inherited.
``bash`
npm install @stdlib/assert-deep-has-property
`javascript`
var deepHasProp = require( '@stdlib/assert-deep-has-property' );
#### deepHasProp( value, path\[, options] )
Returns a boolean indicating if a value has a specified path, either own or inherited.
`javascript
function Foo() {
return this;
}
Foo.prototype.b = {
'c': 'd'
};
var obj = { 'a': new Foo() };
var bool = deepHasProp( obj, 'a.b.c' );
// returns true
bool = deepHasProp( obj, 'a.b.c.d.e' );
// returns false
`
If a key path includes an array, specify the numeric index.
`javascript
var arr = [
{
'a': [
{
'b': [
{ 'c': 'd' },
{ 'e': 'f' }
]
}
]
}
];
var bool = deepHasProp( arr, '0.a.0.b.0.c' );
// returns true
bool = deepHasProp( arr, '0.a.1.b.0.c' );
// returns false
bool = deepHasProp( arr, '0.a.0.b.1.c' );
// returns false
`
The key path may be specified as either a delimited string or a key array.
`javascript
var obj = { 'a': { 'b': { 'c': 'd' } } };
var bool = deepHasProp( obj, [ 'a', 'b', 'c' ] );
// returns true
`
The function accepts the following options:
- sep: key path separator. Default: '.'.
By default, the function assumes . separated key values. To specify an alternative separator, set the sep option.
`javascript
var obj = { 'a': { 'b': { 'c': 'd' } } };
var bool = deepHasProp( obj, 'a/b/c', {
'sep': '/'
});
// returns true
`
#### deepHasProp.factory( path\[, options] )
Returns a function which tests whether a value contains a nested key path, either own or inherited.
`javascript`
var has = deepHasProp.factory( 'a/b/c', {
'sep': '/'
});
#### has( value )
Returns a boolean indicating whether a value contains a nested key path, either own or inherited.
`javascript
var has = deepHasProp.factory( 'a.b.c' );
function Foo() {
return this;
}
Foo.prototype.b = {
'c': 'd'
};
var obj = { 'a': new Foo() };
var bool = has( obj );
// returns true
`
- When provided null or undefined, the function result is always false.
`javascript
var bool = deepHasProp( null, 'a.b.c' );
// returns false
bool = deepHasProp( void 0, 'a.b.c' );
// returns false
`
- Property values other than null or undefined are coerced to objects.
`javascript
var obj = {
'a': 'b'
};
var bool = deepHasProp( obj, 'a.length' );
// returns true
`
- Key path array elements are coerced to strings.
`javascript
var obj = {
'null': false
};
var bool = deepHasProp( obj, [ null ] );
// returns true
obj = {
'[object Object]': false
};
bool = deepHasProp( obj, [ {} ] );
// returns true
`
`javascript
var deepHasProp = require( '@stdlib/assert-deep-has-property' );
var bool = deepHasProp( { 'a': { 'b': { 'c': 'd' } } }, 'a.b.c' );
// returns true
bool = deepHasProp( { 'a': { 'b': { 'c': 'd' } } }, [ 'a', 'b', 'hasOwnProperty' ] );
// returns true
bool = deepHasProp( { 'a': { 'b': { 'c': 'd' } } }, 'a/b/c', {
'sep': '/'
});
// returns true
bool = deepHasProp( { 'a': { 'b': { 'c': 'd' } } }, 'a.b.c.d' );
// returns false
bool = deepHasProp( { 'a': [ { 'b': { 'c': 'd' } } ] }, [ 'a', '0', 'b', 'c', 'd' ] );
// returns false
bool = deepHasProp( { 'a': { 'b': { 'c': 'd' } } }, 'a/b/c/d/e', {
'sep': '/'
});
// returns false
// Create a customized function:
var has = deepHasProp.factory( 'a_b_c', {
'sep': '_'
});
bool = has( { 'a': { 'b': { 'c': 'd' } } } );
// returns true
bool = has( { 'a': [ { 'b': { 'c': 'd' } } ] } );
// returns false
`
*
- [@stdlib/assert-deep-has-own-property][@stdlib/assert/deep-has-own-property]: test whether an object contains a nested key path.
- [@stdlib/assert-has-own-property][@stdlib/assert/has-own-property]: test if an object has a specified property.
- [@stdlib/object-deep-get][@stdlib/object/deep-get]: get a nested property value.
- [@stdlib/utils-deep-pluck][@stdlib/utils/deep-pluck]: extract a nested property value from each element of an object array.
- [@stdlib/object-deep-set][@stdlib/object/deep-set]: set a nested property value.
*
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].
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---
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Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
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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/assert-deep-has-property/tree/deno
[deno-readme]: https://github.com/stdlib-js/assert-deep-has-property/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/assert-deep-has-property/tree/umd
[umd-readme]: https://github.com/stdlib-js/assert-deep-has-property/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/assert-deep-has-property/tree/esm
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[@stdlib/assert/deep-has-own-property]: https://www.npmjs.com/package/@stdlib/assert-deep-has-own-property
[@stdlib/assert/has-own-property]: https://www.npmjs.com/package/@stdlib/assert-has-own-property
[@stdlib/object/deep-get]: https://www.npmjs.com/package/@stdlib/object-deep-get
[@stdlib/utils/deep-pluck]: https://www.npmjs.com/package/@stdlib/utils-deep-pluck
[@stdlib/object/deep-set]: https://www.npmjs.com/package/@stdlib/object-deep-set