javascript unshift

var colors = ["white","blue"];
colors.unshift("red"); //add red to beginning of colors
// colors = ["red","white","blue"]

var person = {	
  	"first_name": "Bob",
	"last_name": "Dylan"
};
person.hasOwnProperty('first_name'); //returns true
person.hasOwnProperty('age'); //returns false

//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]

var name = [ "john" ];
name.unshift( "charlie" );
name.unshift( "joseph", "Jane" );
console.log(name);

//Output will be
[" joseph "," Jane ", " charlie ", " john "]

 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"]

const names = ["Bob", "Cassandra"]

names.unshift("Alex")

names === ["Alex", "Bob", "Cassandra"]

//see https://developer.mozilla.org/fr/docs/Web/JavaScript/Reference/Objets_globaux/Array/unshift

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]

// 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 );

let monTableau = ['un', 'deux','trois', 'quatre'] ;
monTableau.unshift('zero') ; 
//console.log(monTableau) ;
 
 

 let monTableau2D = [
     ['Mark' , 'jeff' , 'Bill'] , 
     ['Zuckerberg' , 'Bezos' , 'Gates']
 ] ;
 monTableau2D[1].unshift('test') ; 
 //console.log(monTableau2D) ;