Answers for "shift unshift concat push pop splice split in angular6"

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"]

javascript prepend string to array

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

names.unshift("Alex")

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