to insert an element at start of array javascript code example

Example 1: js add element to front of array

//Add element to front of array
var numbers = ["2", "3", "4", "5"];
numbers.unshift("1");
//Result - numbers: ["1", "2", "3", "4", "5"]

Example 2: prepend to array javascript

// Build an array of test data.
var data = [ "X" ];

// Unshift data onto the array. Unshift() prepends elements to
// the beginning of the given array. Note that it can take more
// than one argument. In the output, notice that when unshift()
// takes multiple arguments, they are prepended in a right-to-left
// order (mimicing their appearence in the arguments list).
data.unshift( "A" );
data.unshift( "B", "C" );

// Output resultant array.
console.log( data );