how to delete 3 element from start in javascript code example

Example 1: js array.splice first element

var indexToRemove = 0;
var numberToRemove = 1;

arr.splice(indexToRemove, numberToRemove);

Example 2: java script removing first three indexes

var indexToRemove = 0;
var numberToRemove = 1;

arr.splice(indexToRemove, numberToRemove);