checking for null

[jones74]

Hello

Im a action scripting newbie please help.

I am using the following script to pass a color to a layer from the qstring,
this works ok as long as I pass a color, i am trying to check if it is null
then populate it with the default color but it does not work

================================================

onClipEvent (load)

{
myColor = new Color(this);


if(_root.GS6color =null)
{
myColor.setRGB ("0x399880");
}


if(_root.GS6color!="")
{
myColor.setRGB (_root.GS6color);
}

}

===============================================


Any help appreciated


Chris

[UsualSuspect]

try it like this:

if(_root.GS6color ==null())

or like this:

if(_root.GS6color ==undefined)

[Pea]

The best way is to use 3 equals signs. When you use 3 equals it matches not
only the value, but the type of the variable as well. For example, if you have
a boolean value like this:

var myBool = false;
if (myBool==false){ trace('false'); } // This will print 'false'
myBool = null;
if (myBool==false){ trace('false'); } // This will also print 'false'

But if you use === it works fine:

myBool = null;
if (myBool===false){ trace('false'); } // This will not print anything
if (myBool===null){ trace('null'); } // This will print 'null'

NOTE:
If you use just 1 equals sign, you are not checking whether it is null, but
actuall setting it to null.
if (a==b){ // do this }
the above checks if a's value is equal to b's value and does the 'do this'
code if its true

if (a=b){ // do this }
the above SETS a's value to b's value and then ALWAYS does 'do this'

if (a===b){ // do this }
the above checks if a's value is equal to b's value AND a's type is equalt to
b's type, and then does the 'do this' code if its true

Hope it helps,
Pea

[Pea]

when reading aloud, read = as 'set to' and == as 'is equal to', === as 'is exactly equal to'

a=b (a set to b)
a==b (a is equal to b)
a===b (a is exactly equal to b)