JavaScript Strings: Replacing i with 1 and o with 0

We are required to write a function that takes in a string as one and only argument and returns another string that has all ‘i’ and ‘o’ replaced with ‘1’ and ‘0’ respectively.

It’s one of those classic for loop problems where we iterate over the string with its index and construct a new string as we move through.

The code for the function will be −

const string = 'Hello, is it raining in Amsterdam?';
const validate = (str) => {
   let validatedString = '';
   for(let i = 0; i < str.length; i++){
      if(str[i] === 'a'){
         validatedString += '@';
      }else if(str[i] === 'i'){
         validatedString += '!';
      }else{
         validatedString += str[i];
      };
   };
   return validatedString;
};
console.log(validate(string));

The console output for the code will be −

Hello, !s !t r@!n!ng !n Amsterd@m?