substr and substring in javascript code example

Example 1: js substring

// the substring method returns a string out of another string

const str = 'Mozilla';

console.log(str.substring(1, 3));
// expected output: "oz"

console.log(str.substring(2));
// expected output: "zilla"

Example 2: javascript substring vs substr

var string = "This is a string";
var a = string.substring(2, 5); //Start at index 2 and end at index 5
console.log(a); //output "is "
var b = string.substr(2, 5); //Start at index 2 and stop after 5 characters
console.log(b); //output "is is"

Example 3: substring javascript

var str = "Hello world!";
var res = str.substring(1, 4); //ell

Example 4: javascript substring

// zero-based index, 'end' is excluded from result
myString.substring( start, end )