String Methods

properties

let userName = "kalyan\""; // \" is of 1 length 
console.log(userName.length) // This is a property

functions

  console.log(userName.toUpperCase()) // This is function ()

  // Kalyan , index starts from 0
  console.log(userName.slice(1,3)) // last index not included

  console.log(userName.slice(1)) // if second is not given goes to end

  console.log(userName.replace("kal","kir")) // replace , case sensitive

  let friend = "pavan"
  console.log(userName.concat("is good frined of ",friend , " !")) 

  let friend2 = " satish      ";
  console.log(friend2)
  console.log(friend2.trim()) // removes spaces and newlines
  // Others string methods are present in mdn string docs

Strings are immutable

  let a = "ka";
  a[1] = "l";
  console.log(a)
  // All these functions are not mofiying actual srting , string is immutable