How to check whether a value using charAt in JavaScript

Question

I am very new to JavaScript. Presently, I am doing a Program where I want to translate a text into "rovarspracket". i.e) Double every consonant and place an occurrence of "o" in between. For ex: , translate("this is fun") should return the string "tothohisos isos fofunon" . I am not able to get the result as desired. Help me that i would learn.

This is my following code which i tried.

<button type="button" onclick="translate('de')">try it</button>
    <h2 id="ad" />
<script>
            function translate(t)
                {//alert(t.length);exit;
                    var l=t.length;
                    var v=["a","e","i","o","u",""];
                    var b="";
                    for(var i=0;i<l;i++)
                        { //alert(i);exit;
                            var c=t.charAt[i];alert(c);
                            if(v.indexOf(c)!=-1)
                            {   
                                b=(b+(c));
                            }
                            else
                            {
                                b=(b+(c="o"+c));
                            }
                        }

                    document.getElementById("ad").innerHTML=b;
                }

        </script> 

Answer 1

This is something you could do.

function translate(input) {
  var outputString = [];
  var vowels = ['a', 'e', 'i', 'o', 'u'];
  input.split("").forEach(function(charValue) {

    if (vowels.includes(charValue) || charValue == ' ') {
      outputString.push(charValue);
    } else {
      outputString.push(charValue + 'o' + charValue);
    }
  });

  document.querySelector("#output").innerHTML = outputString.join("");
}

div {
  padding: 10px;
}

<button type="button" onclick="window.translate('this is fun')">try it</button>
<div id="output"></div>

If you are specifically looking a solution with charAt function, here it is.

function translate(input) {

  var outputString = [],
    vowels = ['a', 'e', 'i', 'o', 'u'];

  for (var idx = 0; idx < input.length; idx++) {
    var currentChar = input.charAt(idx);
    if (vowels.indexOf(currentChar) === -1 && currentChar != " ") {
      outputString.push(currentChar + "o" + currentChar);
    } else {
      outputString.push(currentChar);
    }
  }
  console.log(outputString.join(""));
}
translate("this is fun");

Answer 2

I've taken the liberty to simplify the functionality for you:

var str = "this is fun",
    arr = str.split(''); // Split the string into an array of separate characters.
    mapped = arr.map(function(c){
        if(["a","e","i","o","u"," "].indexOf(c) == -1) // If the character is a consonant
            return c + 'o' + c; // replace it,
        return c;               // otherwise, just keep the current character.
    }),
    result = mapped.join('');   // Rebuild the string

console.log(result);

Or, a little more compact:

var str = "this is fun",
    result = str.split('').map(function(c){
        return (["a","e","i","o","u"," "].indexOf(c) == -1) ? (c + 'o' + c) : c;
    }).join('');

console.log(result);