append data array javascript

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

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

const array1 = ['a', 'b', 'c'];
const array2 = ['d', 'e', 'f'];
const array3 = array1.concat(array2);

arr = [1, 2, 3, 4]
arr.push(5) // adds element to end

arr.unshift(0) // adds element to beginning

var fruits = ["Banana", "Orange", "Apple", "Mango"];

fruits.push("Kiwi"); .cut-text { 
  text-overflow: ellipsis;
  overflow: hidden;
  white-space: nowrap;
}