JavaScript Array: get "range" of items

Question

Is there an equivalent for ruby's array[n..m] in JavaScript?

For example:

>> a = ['a','b','c','d','e','f','g'] >> a[0..2] => ['a','b','c'] 

Answer 1

Use the array.slice(begin [, end]) function.

var a = ['a','b','c','d','e','f','g']; var sliced = a.slice(0, 3); //will contain ['a', 'b', 'c'] 

The last index is non-inclusive; to mimic ruby's behavior you have to increment the end value. So I guess slice behaves more like a[m...n] in ruby.

Answer 2

The second argument in slice is optional, too:

var fruits = ['apple','banana','peach','plum','pear']; var slice1 = fruits.slice(1, 3);  //banana, peach var slice2 = fruits.slice(3);  //plum, pear 

You can also pass a negative number, which selects from the end of the array:

var slice3 = fruits.slice(-3);  //peach, plum, pear 

Here's the W3 Schools reference link.