how to find mommun lenght code in javascript code example

Example 1: javascript length

var colors = ["Red", "Orange", "Blue", "Green"];
var colorsLength=colors.length;//4 is colors array length 

var str = "bug";
var strLength=str.length;//3 is the number of characters in bug

Example 2: js .substring

let anyString = 'Mozilla'

// Displays 'M'
console.log(anyString.substring(0, 1))
console.log(anyString.substring(1, 0))

// Displays 'Mozill'
console.log(anyString.substring(0, 6))

// Displays 'lla'
console.log(anyString.substring(4))
console.log(anyString.substring(4, 7))
console.log(anyString.substring(7, 4))

// Displays 'Mozilla'
console.log(anyString.substring(0, 7))
console.log(anyString.substring(0, 10))