how to get last /r in javascript code example

Example 1: js remove last character from string

let str = "Hello Worlds";
str = str.slice(0, -1);

Example 2: javascript get last character in string

var hello = "Hello World";
var lastCharOfHello=hello.slice(-1);//d

Example 3: js get last 4 digits

const id = "ctl03_Tabs1";
console.log(id.slice(id.length - 5)); //Outputs: Tabs1
console.log(id.slice(id.length - 1)); //Outputs: 1