# Eval and Webclient
**URL:** https://forum.servoy.com/t/eval-and-webclient/10763
**Category:** Classic Servoy
**Created:** [June 10, 2009, 9:44am UTC](https://forum.servoy.com/t/eval-and-webclient/10763 "2009-06-10T09:44:00Z")
**Posts on this page:** 15
**Page:** 1
### Author:  [@erdione](https://forum.servoy.com/u/erdione)
#### Post date: [June 10, 2009, 9:44am UTC](https://forum.servoy.com/t/eval-and-webclient/10763/1 "2009-06-10T09:44:00Z")
the eval in webclient procude different behaviour between two servers:
**Server Dev**
JDK Information
java.vm.name=Java HotSpot™ Client VM
java.vm.version=11.0-b16
java.vm.info=mixed mode, sharing
java.vm.vendor=Sun Microsystems Inc.
Operating System Information
os.name=Windows 2003
os.version=5.2
os.arch=x86
Everything is ok
**Prod Server**
JDK Information
java.vm.name=Java HotSpot™ Client VM
java.vm.version=11.3-b02
java.vm.info=mixed mode, sharing
java.vm.vendor=Sun Microsystems Inc.
Operating System Information
os.name=Windows 2003
os.version=5.2
os.arch=x86
I’ve got couldn’t eval the string …
Do you have any idea ?
---
### Author:  [@IT2Be](https://forum.servoy.com/u/IT2Be)
#### Post date: [June 10, 2009, 9:51am UTC](https://forum.servoy.com/t/eval-and-webclient/10763/2 "2009-06-10T09:51:24Z")
And what is your question?
---
### Author:  [@erdione](https://forum.servoy.com/u/erdione)
#### Post date: [June 10, 2009, 9:57am UTC](https://forum.servoy.com/t/eval-and-webclient/10763/3 "2009-06-10T09:57:10Z")
Sorry the question wasn’t really clear
I’ve got “couldn’t eval the string …” in the prod server log
Did you already have any strange eval behaviour between two java version ?
---
### Author:  [@martinh](https://forum.servoy.com/u/martinh)
#### Post date: [June 10, 2009, 3:28pm UTC](https://forum.servoy.com/t/eval-and-webclient/10763/4 "2009-06-10T15:28:47Z")
I noticed also a problem with eval()
I already created an issue in the support database. Case 217097
In Eclipse I get the following error:
> Source not found for module [C:/Users/Martin/servoy\_workspace\_development/MOD\_RSS\_HTMLTree/globals.js#645(eval): 1]
---
### Author:  [@jcompagner](https://forum.servoy.com/u/jcompagner)
#### Post date: [June 11, 2009, 7:54am UTC](https://forum.servoy.com/t/eval-and-webclient/10763/5 "2009-06-11T07:54:37Z")
what are you trying to eval?
---
### Author:  [@erdione](https://forum.servoy.com/u/erdione)
#### Post date: [June 11, 2009, 8:07am UTC](https://forum.servoy.com/t/eval-and-webclient/10763/6 "2009-06-11T08:07:42Z")
Ive got mostly the error when i try to eval
myvariable = globals.myfunction()
or
myvariable = globals.myfunction(‘arg1’,‘arg2’)
---
### Author:  [@martinh](https://forum.servoy.com/u/martinh)
#### Post date: [June 11, 2009, 8:15am UTC](https://forum.servoy.com/t/eval-and-webclient/10763/7 "2009-06-11T08:15:14Z")
Johan,
See my case 217097. I added some coding how I tried to eval.
I use eval() in several ways:
```auto
str = 'globals.myMethod'
if (eval(str)) // To test if method exists
{
eval(str)(args)
}
```
But also
```auto
str = 'globals.myVar'
if (eval(str) == 1) // To test if this variable has value 1
```
And also
```auto
str = 'globals.myVar'
if (some test)
str += ' = 1'
else
str += ' = 2';
eval(str) // Set variable to 1 or 2
```
And also
```auto
str = 'globals.myVar'
if (some test)
str += ' [1]'
else
str += ' [2]';
str += ' = 3'
eval(str) // Give some array value the value 3
```
Of course these example are quite simple, but it shows the way eval() is used. I worked fine in 3.5 and some of the coding was originally written in 2.2!
By the way, I tried also the following and that is working, so it looks like it is perhaps eval() in combination with if-statement
```auto
str = 'globals.myVar'
val = eval(str)
if (val == 1) // To test if this variable has value 1
```
---
### Author:  [@jcompagner](https://forum.servoy.com/u/jcompagner)
#### Post date: [June 11, 2009, 8:23am UTC](https://forum.servoy.com/t/eval-and-webclient/10763/8 "2009-06-11T08:23:48Z")
> erdione:
> Ive got mostly the error when i try to eval
> myvariable = globals.myfunction()
> or
> myvariable = globals.myfunction(‘arg1’,‘arg2’)
so you are doing
eval(“myvariable = globals.myfunction()”);
why would you eval that?
---
### Author:  [@jcompagner](https://forum.servoy.com/u/jcompagner)
#### Post date: [June 11, 2009, 8:26am UTC](https://forum.servoy.com/t/eval-and-webclient/10763/9 "2009-06-11T08:26:06Z")
> martinh:
> Johan,
>
> See my case 217097. I added some coding how I tried to eval.
>
> I use eval() in several ways:
why are you evalling that kind of stuff like that?
why not just
if (globals[‘mymethod’])
{
globals’mymethod’
}
way faster then evalling.
---
### Author:  [@erdione](https://forum.servoy.com/u/erdione)
#### Post date: [June 11, 2009, 8:30am UTC](https://forum.servoy.com/t/eval-and-webclient/10763/10 "2009-06-11T08:30:00Z")
I eval that because for example myfunction can be dynamically change (in my case database driven)
---
### Author:  [@jcompagner](https://forum.servoy.com/u/jcompagner)
#### Post date: [June 11, 2009, 9:01am UTC](https://forum.servoy.com/t/eval-and-webclient/10763/11 "2009-06-11T09:01:57Z")
```auto
myvariable = globals[dynamicname]();
```
should work fine and even better/faster.
---
### Author:  [@martinh](https://forum.servoy.com/u/martinh)
#### Post date: [June 11, 2009, 9:03am UTC](https://forum.servoy.com/t/eval-and-webclient/10763/12 "2009-06-11T09:03:35Z")
> jcompagner:
>
> > martinh:
> > Johan,
> >
> > See my case 217097. I added some coding how I tried to eval.
> >
> > I use eval() in several ways:
>
> why are you evalling that kind of stuff like that?
>
> why not just
>
> if (globals[‘mymethod’])
> {
> globals’mymethod’
> }
>
> way faster then evalling.
Because mymethod is a variable name (callback method)
---
### Author:  [@jcompagner](https://forum.servoy.com/u/jcompagner)
#### Post date: [June 11, 2009, 9:27am UTC](https://forum.servoy.com/t/eval-and-webclient/10763/13 "2009-06-11T09:27:23Z")
```auto
globals[variableHoldingTheNameOfTheMethodYouWantToCall]()
```
really guys, eval is almost never needed…
---
### Author:  [@martinh](https://forum.servoy.com/u/martinh)
#### Post date: [June 11, 2009, 9:55am UTC](https://forum.servoy.com/t/eval-and-webclient/10763/14 "2009-06-11T09:55:48Z")
OK, I’ll see if I can change my code, but how about the following:
```auto
var _method = arguments[0];
if (eval(_method))
{
eval(_method)()
}
```
And the argument that I get, is a method on a form
So Arguments 0 = forms.myForm.myMethod
---
### Author:  [@jcompagner](https://forum.servoy.com/u/jcompagner)
#### Post date: [June 11, 2009, 10:02am UTC](https://forum.servoy.com/t/eval-and-webclient/10763/15 "2009-06-11T10:02:53Z")
```auto
function test()
{
var name = "called"; // arguments[0];
var argument = "from test";
this[name](argument);
}
function called()
{
application.output("called with argument: " + arguments[0])
}
```