View Full Version : +=

07-29-2011, 08:22 PM
how can you make a += work so if you add 5+5 with += it would come out as 55 how would you make it come out as 10?

07-29-2011, 11:59 PM
It will automatically come out as 10 if you make sure that both sides of the "+=" are numeric values. If you (for example) read the value of an input box, it will always be a string (even if you entered a number). You'll have to convert it into a numeric value before adding 5 to it


var myValue = document.getElementById('myinput').value;
myValue = Number(myValue); // convert it to a numeric value if possible, otherwise it will be "NaN"
myValue += 5; // mathematically add 5 to this value

07-30-2011, 12:09 AM