Hi,
pressing +1 just adds an 1 to the text. 10 becomes 101
pressing -1 neatly subtracts 1. 10 becomes 9
what is the mistake?
tia,
John
plusmin.hype.zip (12.0 KB)
Hi,
pressing +1 just adds an 1 to the text. 10 becomes 101
pressing -1 neatly subtracts 1. 10 becomes 9
what is the mistake?
tia,
John
plusmin.hype.zip (12.0 KB)
Welcome to javascript – try this, it works…
var x = hypeDocument.getElementById("qty").innerHTML;
x = x * 1 + 1; // the plus sign is used for concatenation
hypeDocument.getElementById("qty").innerHTML = x;
I think the problem is that you are working in effect with strings. so the plus symbol is being used to concatanate the two strings.
There are a couple of ways to force the string into numbers but the simplest in this case is to just do:
var x = hypeDocument.getElementById("qty").innerHTML;
x++;
hypeDocument.getElementById("qty").innerHTML = x;
If you wanted to do something like:
var x = hypeDocument.getElementById("qty").innerHTML;
x = x + 400;
hypeDocument.getElementById("qty").innerHTML = x;
Then you would need to cast x into a number. One way of doing it is :
var x = hypeDocument.getElementById("qty").innerHTML;
x = Number(x) + 400;
hypeDocument.getElementById("qty").innerHTML = x;
thank you @gasspence and @MarkHunte. You just saved my weekend!
I really need to dive deeper into JS.