shift and unshift in javascript code example
Example 1: javascript add new array element to start of array
var colors = ["white","blue"];
colors.unshift("red"); //add red to beginning of colors
// colors = ["red","white","blue"]
Example 2: javascript prepend string to array
const names = ["Bob", "Cassandra"]
names.unshift("Alex")
names === ["Alex", "Bob", "Cassandra"]
Example 3: array.unshift in javascript
//The unshift() method adds one or more elements to the beginning of an array
//and returns the new length of the array.
const array1 = [1, 2, 3];
console.log(array1.unshift(4, 5));
// expected output: 5
console.log(array1);
// expected output: Array [4, 5, 1, 2, 3]
Example 4: unshift method in javascript
var name = [ "john" ];
name.unshift( "charlie" );
name.unshift( "joseph", "Jane" );
console.log(name);
//Output will be
[" joseph "," Jane ", " charlie ", " john "]
Example 5: javascript unshift
let array = ["A", "B"];
let variable = "what you want to add";
//Add the variable to the beginning of the array
array.unshift(variable);
//===========================
console.log(array);
//output =>
//["what you want to add" ,"A", "B"]
Example 6: 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 );