Can't figure out whats wrong with my program

Question

Hey guys when i run this program it doesnt add my numbers, basically im supposed to print the salesman with the highest selling, and the most selling car. For example, when i type 50 amount for each car at the end it prints : 050505050 rather summing it up to a 200..

function salesPerson(name, id, amount) {
            this.name = name;
            this.id = id;
            this.amount = amount;
        };


    //Create car array for each brand
        var Car = new Array(4);

        //Create array of salePersons
        var Person = new Array(2);

        //Every element in the array is a object type salesPerson
        for (var i = 0; i < Person.length; i++) {
            Person[i] = new salesPerson("", 0, 0);
        }

        var temp = 0;

        var m = 0;
        var a = 0;
        var p = 0;
        var b = 0;



        for(var i = 0; i < Person.length; i++){
           Person[i].name = prompt("Enter salesman name: ");
           Person[i].id = prompt("Enter salesman id: ");

           temp = prompt("Enter Mercedes-Benz amount: ");
           Person[i].amount += temp;
           m += temp;

           temp = prompt("Enter Audi amount: ");
           Person[i].amount += temp;
           a += temp;

           temp = prompt("Enter Porsche amount: ");
           Person[i].amount += temp;
           p += temp;

           temp = prompt("Enter BMW amount: ");
           Person[i].amount += temp;
           b += temp;

        }

        var max = 0;
        var name = "";

        for (var i = 0; i < Person.length; i++) {
            if (Person[i].amount > max) {
                max = Person[i].amount;
                name = Person[i].name;
            }
        }

        alert("The best salesperson of the month is " + name + ", with the sales amount of $" + max);

Answer 1

The result of prompt is a string so + is concatenate. A very crude fix is to just do something like:

temp = +prompt("Enter Mercedes-Benz amount: ");

where the + causes a conversion. Note that this is very crude - it doesn't do any checking or error handling.

Answer 2

You need to convert temp to number ; Use unary operator + or parseInt() for that.

 for(var i = 0; i < Person.length; i++){
           Person[i].name = prompt("Enter salesman name: ");
           Person[i].id = prompt("Enter salesman id: ");

           temp = +prompt("Enter Mercedes-Benz amount: ");
           Person[i].amount += temp;
           m += temp;

           temp = +prompt("Enter Audi amount: ");
           Person[i].amount += temp;
           a += temp;

           temp = +prompt("Enter Porsche amount: ");
           Person[i].amount += temp;
           p += temp;

           temp = +prompt("Enter BMW amount: ");
           Person[i].amount += temp;
           b += temp;

        }

Working Fiddle

Answer 3

before adding parse string as Integer.

 function salesPerson(name, id, amount) { this.name = name; this.id = id; this.amount = amount; }; //Create car array for each brand var Car = new Array(4); //Create array of salePersons var Person = new Array(2); //Every element in the array is a object type salesPerson for (var i = 0; i < Person.length; i++) { Person[i] = new salesPerson("", 0, 0); } var temp = 0; var m = 0; var a = 0; var p = 0; var b = 0; for(var i = 0; i < Person.length; i++){ Person[i].name = prompt("Enter salesman name: "); Person[i].id = prompt("Enter salesman id: "); temp = parseInt(prompt("Enter Mercedes-Benz amount: ")); Person[i].amount += temp; m += temp; temp = parseInt(prompt("Enter Audi amount: ")); Person[i].amount += temp; a += temp; temp = parseInt(prompt("Enter Porsche amount: ")); Person[i].amount += temp; p += temp; temp = parseInt(prompt("Enter BMW amount: ")); Person[i].amount += temp; b += temp; } var max = 0; var name = ""; for (var i = 0; i < Person.length; i++) { if (Person[i].amount > max) { max = Person[i].amount; name = Person[i].name; } } alert("The best salesperson of the month is " + name + ", with the sales amount of $" + max); 

Answer 4

When you take an input from the user, it is received as a string. You need to convert this input to an int. This can be done by using parseInt(value, radix) . To know more about parseInt function see http://www.w3schools.com/jsref/jsref_parseInt.asp