Function that returns the opposite letter

Question

I want to write a function that returns alternating characters, so for instance:

"hello world".toAlternatingCase() === "HELLO WORLD"
"HELLO WORLD".toAlternatingCase() === "hello world"
"HeLLo WoRLD".toAlternatingCase() === "hEllO wOrld"

Here is my try

const alternatingCase = function (string) {
  let newword = "";

  for (i = 0; i<string.length; i++) {
     if (string.charAt(i).toUpperCase())
    {
    newword+= string.charAt(i).toLowerCase()
    }

   else 
   {
   newword+=string.charAt(i).toUpperCase()
   }
  }
  return newword  
}

When invoked, the function unfortunately only returns the string itself, not sure what I'm doing wrong though, thanks very much for reading or even helping out!

Answer 1

You need to check if the caracter is uppercase and take then lower case.

Don't forget to declare all variables.

This approach uses a conditional (ternary) operator ?: where a condition is used to return two different expressions.

 const alternatingCase = function(string) { let newword = ""; for (let i = 0; i < string.length; i++) { let character = string[i]; newword += character === character.toUpperCase()? character.toLowerCase(): character.toUpperCase(); } return newword; } console.log(alternatingCase('Test'));

If you really need to use the function as prototype of string, you need to assign the function to String.prototype and the wanted method. For this you need to address this , to get the value of the string.

 String.prototype.alternatingCase = function() { let newword = ""; for (let i = 0; i < this.length; i++) { let character = this[i]; newword += character === character.toUpperCase()? character.toLowerCase(): character.toUpperCase(); } return newword; } console.log('Test'.alternatingCase());

Answer 2

you've done the compression wrong

checkout this

 function alternatingCase(string) { let newword = ""; for (i = 0; i < string.length; i++) { const c = string.charAt(i); if (c === c.toUpperCase()){ newword += c.toLowerCase() } else { newword += c.toUpperCase() } } return newword; } console.log(alternatingCase("TesT"));

Answer 3

All you need to update is your condition to if (string.charAt(i) === string.charAt(i).toUpperCase()) . You have to compare your uppercase letter to original letter.

 const alternatingCase = function(string) { let newword = ""; for (i = 0; i < string.length; i++) { if (string.charAt(i) === string.charAt(i).toUpperCase()) { newword += string.charAt(i).toLowerCase() } else { newword += string.charAt(i).toUpperCase() } } return newword } console.log(alternatingCase("HeLLo WoRLD"));