Possible ways to iterate a string in JavaScript

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First, we need to understand the basic ways to get the char at a particular index in the string. There are two ways basically.

str.chatAt(index)

  • charAt() method returns a new string, at particular given index.
  • Supported in Old browsers (IE7 too)
  • If no index passed, takes index, by default 0
  • If out of range index, returns empty string

Bracket Notation (str[index])

  • Bracket method returns char at particular given index.
  • It was introduced in ECMAScript 2015 but breaks in old browsers
  • If no index passed, throws syntax error
  • If out of range index, returns undefined

Iterating over the string -

  1. For Loop

    const str = "pankaj";
    for (let index = 0; index < str.length; index ++) {
            console.log(str[index]) // str.charAt(index)
    }
    
  2. for..of

    const str = "pankaj";
    for (let c of str ) {
         console.log(c);
    }
    
  3. forEach()

    const str = "pankaj";
    [...str].forEach( (c) => console.log(c) );
    

BONUS => Downside of bracket notation is that, it cant be used to assign a character

let str = "pankaj"
str[0] = "t"
console.log(str) // "pankaj"

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