Javascript calculator problem

Megan posted this at 13:34 — 22nd August 2003.

Joined: Jun 1999

I'm having a little problem with a javascript calculator and I'm wondering if anyone could help me. The problem is that if the user inputs something with brackets but doesn't close them (i.e. only one bracket in the string), you get a javascript error.

http://www.meganjack.com/sa_1b1.html

How can I fix this? I'm thinking you could detect if there is only one bracket in the string and give an alert about it to the user. Kind of like validating a form. Sorry, I haven't done any real javascripting in ages.

Thanks!

Megan
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druagord posted this at 17:05 — 22nd August 2003.

He has: 335 posts

Joined: May 2003

try this it should work but i didn't test it

function calcit() {
strExp = document.calc.shownum.value;
intopen =0;
intclose=0;
for(i=0;i<strExp.length;i++)
{
   if(strExp.charAt(i)=='(')
   {
       intopen++;
   }
   else
   {
      if(strExp.charAt(i)==')')
      {
         intclose++;
      }
   }
}

if(intclose!=intopen)
{
document.calc.shownum.value ="error";
return;
}
		   if (document.calc.exp.value == "x") {
			document.calc.shownum.value = eval(document.calc.shownum.value);
		   }
		   else {
			document.calc.shownum.value = eval('Math.pow(' + document.calc.exp.value + ',' + document.calc.shownum.value + ')');
			document.calc.exp.value = "x";
		   }
		}

IF , ELSE , WHILE isn't that what life is all about

Megan posted this at 17:21 — 22nd August 2003.

She has: 11,421 posts

Joined: Jun 1999

That seems to work! Thanks a lot!

But, another problem - an error occurs when the user tries to put in more than one operator (i.e. 9+*). Any way to fix that too? I'm trying to figure out what you did there but it's a little bit beyond me I've tried looking for a different script but I can't seem to find one with the xy function. I might just decide to take out the calculator (seeing as how the users probably have a real one sitting on their desks anyway).