# jQuery.merge()

Categories: Utilities

## jQuery.merge( first, second ) Returns: Array

Description: Merge the contents of two arrays together into the first array.

- #### version added: 1.0jQuery.merge( first, second )

  firstThe first array to merge, the elements of second added.

  secondThe second array to merge into the first, unaltered.

The `$.merge()` operation forms an array that contains all elements from the two arrays. The orders of items in the arrays are preserved, with items from the second array appended. The `$.merge()` function is destructive. It alters the first parameter to add the items from the second.

If you need the original first array, make a copy of it before calling `$.merge()`. Fortunately, `$.merge()` itself can be used for this duplication:

    var newArray = $.merge([], oldArray);

This shortcut creates a new, empty array and merges the contents of oldArray into it, effectively cloning the array.

Prior to jQuery 1.4, the arguments should be true Javascript Array objects; use `$.makeArray` if they are not.

### Examples:

#### Example: Merges two arrays, altering the first argument.

    $.merge( [0,1,2], [2,3,4] )

#### Result:

    [0,1,2,2,3,4]

#### Example: Merges two arrays, altering the first argument.

    $.merge( [3,2,1], [4,3,2] )

#### Result:

    [3,2,1,4,3,2]

#### Example: Merges two arrays, but uses a copy, so the original isn't altered.

    var first = ['a','b','c'];
    var second = ['d','e','f'];
    $.merge( $.merge([],first), second);

#### Result:

    ["a","b","c","d","e","f"]