// Merge the contents of two arrays together into the first array.
jQuery.merge( first, second );
// Merge two arrays
$.merge( [ 0, 1, 2 ], [ 2, 3, 4 ] ); // [ 0, 1, 2, 2, 3, 4 ]
// Get a copy of an array
let newArray = $.merge( [], [ 1, 2, 3, 4 ] );
$.merge( [ 3, 2, 1 ], [ 4, 3, 2 ] )