rekeyViews

Create an array containing views with renamed keys for every element in a provided array.

Installation

npm install @stdlib/array-base-rekey-views

Usage

var rekeyViews = require( '@stdlib/array-base-rekey-views' );

rekeyViews( arr, mapping )

Returns an array containing views with renamed keys for every element in a provided array.

var x = [
    {
        'x': 1,
        'y': 2
    },
    {
        'x': 3,
        'y': 4
    }
];
var mapping = {
    'x': 'a',
    'y': 'b'
};

var out = rekeyViews( x, mapping );
// returns [ <Object>, <Object> ]

var v0 = out[ 0 ].toJSON();
// returns { 'a': 1, 'b': 2 }

var v1 = out[ 1 ].toJSON();
// returns { 'a': 3, 'b': 4 }

// Mutate the first element in the input array:
x[ 0 ].x = 5;

v0 = out[ 0 ].toJSON();
// returns { 'a': 5, 'b': 2 }

// Set a view property:
out[ 1 ].b = 'beep';

v1 = out[ 1 ].toJSON();
// returns { 'a': 3, 'b': 'beep' }

var y = x.slice();
// returns [ { 'x': 5, 'y': 2 }, { 'x': 3, 'y': 'beep' } ]

The function has the following parameters:

• arr: input array.
• mapping: object mapping existing keys to new key names.

Notes

• The function returns views having only those keys which are present in a provided mapping object. Any keys which are not present in the provided mapping object, but are present in the original objects, are omitted during view creation.
• The function assumes that each object has the keys specified in a provided mapping object.
• Each view in the returned array shares the same memory as the corresponding elements in the input arrays. Accordingly, mutation of either an array element or a view will mutate the other.

Examples

var discreteUniform = require( '@stdlib/random-base-discrete-uniform' );
var filledBy = require( '@stdlib/array-base-filled-by' );
var rekeyViews = require( '@stdlib/array-base-rekey-views' );

function clbk( idx ) {
    return {
        'x': idx,
        'y': discreteUniform( 0, 10 )
    };
}

var x = filledBy( 10, clbk );
var mapping = {
    'x': 'a',
    'y': 'b'
};

var out = rekeyViews( x, mapping );
// returns [...]

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 © 2016-2026. The Stdlib Authors.