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JavaScript Introducing the Practice

John Bastian Bolhano
John Bastian Bolhano
4,800 Points
Posted by John Bastian Bolhano
John Bastian Bolhano
4,800 Points

Why did the type of variable change?

In the multiplication and division the variable seems to work as expected while with addition and substraction the variables seems to be as string resulting it as NaN.

alert("Let's do some math!");
var input1 = parseInt(prompt("Please type a number"));
var input2 = parseInt(prompt("Please type another number"));
console.log(typeof(input1,input2));
var message = "<h1>Math with the numbers " + input1 + " and " + input2 + "</h1>"
            + input1 + " + " + input2 + " = " + input1 + input2 + "<br>"
            + input1 + " - " + input2 + " = " + input1 - input2 + "<br>"
            + input1 + " * " + input2 + " = " + input1 * input2 + "<br>"
            + input1 + " / " + input2 + " = " + input1 / input2 + "<br>";
document.write(message);

1 Answer

Dale Severude
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Dale Severude
Full Stack JavaScript Techdegree Graduate 71,349 Points
Dale Severude
.a{fill-rule:evenodd;}techdegree seal-36
Dale Severude
Full Stack JavaScript Techdegree Graduate 71,349 Points

To fix your code you need to add parenthesis around your calculations. The addition is concatenating them together as strings. The subtraction is creating a NAN.

(input1 + input2)
(input1 - input2)
John Bastian Bolhano
John Bastian Bolhano
4,800 Points
John Bastian Bolhano
John Bastian Bolhano
4,800 Points

Thanks, man. I should have thought this.