javascript append item to array

1var colors=["red","white"];
2colors.push("blue");//append 'blue' to colors

1var colors=["red","blue"];
2var index=1;
3
4//insert "white" at index 1
5colors.splice(index, 0, "white");   //colors =  ["red", "white", "blue"]
6

1var colors= ["red","blue"];
2	colors.push("yellow"); //["red","blue","yellow"]

1var colors= ["red","blue"];
2	colors.push("yellow"); 

1const fruits = ["Banana", "Orange", "Apple", "Mango"];
2fruits.push("Kiwi");

1var arr1 = ["Hello"," "];
2var arr2 = ["World","!"];
3var both = arr1.concat(arr2);
4//both = ["Hello"," ","World","!"];