mapValues
Map values from one object to a new object having the same keys.
Usage
var mapValues = require( '@stdlib/utils/map-values' );
mapValues( obj, transform )
Maps values from one object
to a new object
having the same keys.
function transform( value, key ) {
return key + value;
}
var obj1 = {
'a': 1,
'b': 2
};
var obj2 = mapValues( obj1, transform );
// returns { 'a': 'a1', 'b': 'b2' }
The transform
function is provided three arguments:
- value: object value corresponding to
key
. - key: object key.
- obj: the input object.
Notes
- Key iteration order is not guaranteed, as
object
key enumeration is not specified according to the ECMAScript specification. In practice, however, most engines use insertion order to sort anobject
's keys, thus allowing for deterministic return values. - The function only maps values assigned to own properties. Hence, the function does not map values for inherited properties.
- The function shallow copies key values.
Examples
var mapValues = require( '@stdlib/utils/map-values' );
function transform( value, key ) {
return key + ':' + value;
}
var obj1 = {
'a': 'beep',
'b': 'boop',
'c': 'foo',
'd': 'bar'
};
var obj2 = mapValues( obj1, transform );
console.dir( obj2 );
// => { 'a': 'a:beep', 'b': 'b:boop', 'c': 'c:foo', 'd': 'd:bar' }