check if function name which is stored in a variable exist

[andho]

for example in this code:

var funcName = "myFunc";
 
if (typeof eval(funcName) == 'function') {
  evail(funcName + "()"); // this will call myFunc
}

but its returns runtime error: myFunc does not exist

what im trying to do is call the function specified in the funcName variable (which is myFunc).
I can call is using

eval(funcName)

but i want to check if it exists before i call it

[gits]

hi ...

welcome to TSDN ...

why do you use eval? ... in case you don't need it ... and i think so ... you may do something like the following:

function myFunc() {
   alert('test');
}
 
var funcName = myFunc;
 
if (typeof funcName != 'undefined') {
    funcName();
}
 

kind regards

[pbmods]

Heya, andho. Welcome to TSDN!

Have a look at this article.

[andho]

thanks for the welcome and quick replies. checked that article. but heres my real problem.
i have this HTML:
[HTML]<input type="text" name="single" id="single" onkeydown="validate(event, 'number');" />[/HTML]
On the onkeydown event i call validate function which has two parameters. One is the event and the other is the type of validation to execute, in this case 'number'. It could be varchar or date depending on the how the user wants to use it.
now i need to check if 'number' is a function and then call it:

function validate(e, type) {
    eval(type + "();");
}

im using eval because the type string could be any validation function in this library

[dmjpro]

Ok!
Have a look at this modified Code.

function validate(e, type) {
    var command_str = "if(typeof " + type + " == 'function') " + type + "();";
        eval(command_str);
}
 

Good Luck with your try. :-)

Kind regards,
Dmjpro.

[gits]

hi ...

have a look at the following example that avoids the eval (test it in FF):

<script type="text/javascript">
function number(e) {
    alert(e.target.nodeName);
}
 
function validate(e, func) {
    if (typeof window[func] != 'undefined') {
        window[func](e);
    }
}
</script>
 
<input type="button" value="test_button" onclick="validate(event, 'number');"/>
 

kind regards

[dmjpro]

hi ...

have a look at the following example that avoids the eval (test it in FF):

<script type="text/javascript">
function number(e) {
    alert(e.target.nodeName);
}
 
function validate(e, func) {
    if (typeof window[func] != 'undefined') {
        window[func](e);
    }
}
</script>
 
<input type="button" value="test_button" onclick="validate(event, 'number');"/>
 

kind regards

hi Gits :-)
Does not eval work in FF.

Kind regards,
Dmjpro.

[andho]

hey it works like a charm, but really the if statement is a little longer but i go with that. But is there a better way if i have a very long if statement

[gits]

of course it works ... but have a look at it and replace the 'a' in it with an 'i' ... never use eval when there is no need for it ... it evaluates everything and it may lead to the phenomenon to use it for everything ... but in nearly all cases you simply don't need it ...

kind regards

[gits]

and of course you could use:

function validate(e, func) {
    if (typeof window[func] == 'function') {
        window[func](e);
    }
}
 

[andho]

hey window[func] is nice. havent seen it anywhere before
how is the compatibility of window[func] with all the browsers.

[gits]

i think it has to work with all browsers ... its simply using the scope! ... you define your function in the window-context and you may ask the window for the function as its property ... you may consider the window as an array of methods ;)

kind regards

:: while it's an object of course :)

[pbmods]

Heya, andho.

Have a look at this article.