get initial 10 character for string in javascript code example

Example 1: javascript get first 10 characters of string

var str = "Hello world That is reallly neat!";
var res = str.substring(0, 5);//get first 5 chars

Example 2: reactjs cut part of string

var str = "Hello world!";

var res = str.substring(1, 4);

// res value is "ell"