var a = [1, 2, 3, 4];<br /> a.unshift(0);<br /> a; // => [0, 1, 2, 3, 4]<br />

const names = [“Bob”, “Cassandra”]</p> <p>names.unshift(“Alex”)</p> <p>names === [“Alex”, “Bob”, “Cassandra”]

// Build an array of test data.<br /> var data = [ “X” ];</p> <p>// Unshift data onto the array. Unshift() prepends elements to<br /> // the beginning of the given array. Note that it can take more<br /> // than one argument. In the output, notice that when unshift()<br /> // takes multiple arguments, they are prepended in a right-to-left<br /> // order (mimicing their appearence in the arguments list).<br /> data.unshift( “A” );<br /> data.unshift( “B”, “C” );</p> <p>// Output resultant array.<br /> console.log( data );

var a = [1, 2, 3, 4];<br /> a.unshift(0);<br /> a; // => [0, 1, 2, 3, 4]