string_count.js

//We will create a function to be extended to all String Objects
//This Injects the function into the String Object so any String Object will be able to call count
String.prototype.count = function countV() {
    //store Object
    var StringObj = this;
    //Because countV is a function that will extend the String Object this will refer to the String itself if
    //Our Json Object to Hold Data this is more efficient as you can return multiple results in one Object
    var letter = { vowel: 0, consonant: 0 };
    //Our loop
    for (var i = 0; i < StringObj.length; i++) //Remember StringObj holds the String Object
    {
        //This will compare the characters and determine which is consonant and vowel by updating the Json Object
        if (StringObj[i] == "a" || StringObj[i] == "e" || StringObj[i] == "i" || StringObj[i] == "o" || StringObj[i] == "u")
            letter.vowel++; //increment the data by 1 if vowel found
        else
            letter.consonant++; //increment the data by 1 if consonant found
    }
    //do not use this.letter because this means String and letter is not an Object of String its an inner variable so we simple use letter
    return letter;
};
//Testing Our function
var r = new String("Welcome");
console.log(r.count()) //returns the letter Json data
console.log(r.count().vowel) //returns vowel