@stdlib/utils-deep-get

About stdlib...

We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.

The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.

When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.

To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!

Deep Get

Get a nested property value.

Installation

npm install @stdlib/utils-deep-get

Usage

var deepGet = require( '@stdlib/utils-deep-get' );

deepGet( obj, path[, options] )

Returns a nested property value.

var obj = { 'a': { 'b': { 'c': 'd' } } };

var val = deepGet( obj, 'a.b.c' );
// returns 'd'

For paths including arrays, specify the numeric index.

var arr = [
    { 'a': [ {'x': 5} ] },
    { 'a': [ {'x': 10} ] }
];

var val = deepGet( arr, '1.a.0.x' );
// returns 10

The key path may be specified as either a delimited string or a key array.

var obj = { 'a': { 'b': { 'c': 'd' } } };

var val = deepGet( obj, [ 'a', 'b', 'c' ] );
// returns 'd'

The function accepts the following options:

• sep: key path separator. Default: '.'.

By default, the function assumes dot separated key values. To specify an alternative separator, set the sep option.

var obj = { 'a': { 'b': { 'c': 'd' } } };

var val = deepGet( obj, 'a/b/c', {
    'sep': '/'
});
// returns 'd'

deepGet.factory( path[, options] )

Creates a reusable deep get function. The factory method ensures a deepGet function is configured identically by using the same set of provided options.

var dget = deepGet.factory( 'a/b/c', {
    'sep': '/'
});

dget( obj )

Returns a nested property value.

var dget = deepGet.factory( 'a.b.c' );

var obj = { 'a': { 'b': { 'c': 'd' } } };

var val = dget( obj );
// returns 'd'

Examples

var randu = require( '@stdlib/random-base-randu' );
var deepGet = require( '@stdlib/utils-deep-get' );

var data;
var keys;
var val;
var i;

data = new Array( 100 );
for ( i = 0; i < data.length; i++ ) {
    data[ i ] = {
        'x': Date.now(),
        'y': [ randu(), randu(), i ]
    };
}

keys = [ 0, 'y', 2 ];
for ( i = 0; i < data.length; i++ ) {
    keys[ 0 ] = i;
    val = deepGet( data, keys );
    console.log( val );
}

---

See Also

• @stdlib/utils-deep-pluck: extract a nested property value from each element of an object array.
• @stdlib/utils-deep-set: set a nested property value.

---

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.