Push a string into an array. If there is already an instance of the string in the array, append an appropriate number to the end of the string first.

append.js

function append(arr, string){
    // if the string does exist in the array ..
    if(arr.indexOf(string) != -1){
        var n = 2;
        var fin = false;

        // .. loop indefinitely until we decide we have found a usable number.
        while(!fin){
            // if the string + the number doesn't exist
            if(arr.indexOf(string+' ('+n+')') == -1){
                // add it
                arr.push(string+' ('+n+')');
                // and end the loop.
                fin = true;
                
            // if the string + number does exist, then increase n and repeat the loop
            }else{
                n += 1;
            }
        }
    
    // if the string doesn't exist in the array ..
    }else{
        // ..add it
        arr.push(string);
    }
}