Question

I’ve just taken over a project from another developer and the code has a lot of if statements like this:

if( value != null || value != "" || value != undefined )
{
    doSomeThing();
}

Which while ok, does get a bit messy when used everywhere. Is there a better, neater way to write this? I was thinking of this

if( value.length > 0 || value != undefined )
{
    doSomeThing();
}

What do you all think?

Thanks

Stephen

Answer 1

It’s nearly that, but with if( value.length > 0 || value != undefined ) when value is null value.length will thhrow a runtime error TypeError: Error #1009 as you are trying to access a property on a null value.

so you have to check before that the value is non null as for example :

if (value!=null&&value.length>0) {doSomeThing();}

or another form shorter :

if ((value||"").length>0) {doSomeThing();}

One note:
Unless the type of value is *, it can’t take the value undefined, it will be null.

var str:String=undefined;
trace(str==null); // will output true