This is a simple JavaScript getter/setter function for retrieving or changing a value in an array.
npm install value-at --save
Quick guide to the syntax:
valueAt(array, index[, replacementValue][, isCloned])
var valueAt = require('value-at');
var array = [1, 2, 3, 4, 5];
var value = valueAt(array, 1);
// value = 2
That isn't all that special since you can do the same thing with native JavaScript by just using array[1]
.
The advantage this has is that it also works for negative index values.
var valueAt = require('value-at');
var array = [1, 2, 3, 4, 5];
var value = valueAt(array, -2);
// value = 4
var valueAt = require('value-at');
var array = [1, 2, 3, 4, 5];
var newArray = valueAt(array, 1, "a");
// array = [1, 2, 3, 4, 5];
// newArray = [1, "a", 3, 4, 5];
Note that valueAt
doesn't change the original array by default. It returns with an altered shallow clone of the original array.
var valueAt = require('value-at');
var array = [1, 2, 3, 4, 5];
var newArray = valueAt(array, -2, "b");
// array = [1, 2, 3, 4, 5];
// newArray = [1, 2, 3, "b", 5];
If you do want to alter the original array, set the 4th parameter to false
.
var valueAt = require('value-at');
var array = [1, 2, 3, 4, 5];
valueAt(array, -2, "b", false);
// array = [1, 2, 3, "b", 5];