when to use 2 equal signs and when to use 3

[lkrubner@geocities.com]

When I had these two lines in my code:


if ($executed == "The command didn't exist") {
$this->core->error("In CommandRenderAl lActionsInAnArr ay we sought
the command '$commandName' but ExteriorCommand s could not find it. It
returned the value: '$executed'.", "CommandRenderA llActionsInAnAr ray");



I was getting this on screen:


# CommandRenderAl lActionsInAnArr ay threw this error: In
CommandRenderAl lActionsInAnArr ay we sought the command
'checkToSeeIfTh isIsTheFirstLog in' but ExteriorCommand s could not find
it. It returned the value: '1'.







But if I change the first line to this:


if ($executed === "The command didn't exist") {



then it works correctly.


Why does this need 3 equal signs? Why doesn't 2 suffice? I've done
string comparisons before and I've never had to use 3 equal signs
before.

[Janwillem Borleffs]

Re: when to use 2 equal signs and when to use 3

lkrubner@geocit ies.com wrote:[color=blue]
> Why does this need 3 equal signs? Why doesn't 2 suffice? I've done
> string comparisons before and I've never had to use 3 equal signs
> before.
>[/color]

Have a close look at $executed. My guess is that it contains a boolean and
because a non-empty string equals boolean true with the lose ==
comparisation, you are getting the unexpected result. with === you are not
only comparing the values but also the types.


JW

[lkrubner@geocities.com]

Re: when to use 2 equal signs and when to use 3

>>>>>>>>>>>>> >>[color=blue]
> Why does this need 3 equal signs? Why doesn't 2 suffice? I've done
> string comparisons before and I've never had to use 3 equal signs
> before.[/color]

Have a close look at $executed. My guess is that it contains a boolean
and
because a non-empty string equals boolean true with the lose ==
comparisation, you are getting the unexpected re[color=blue][color=green][color=darkred]
>>>>>>>>>>>>> >>[/color][/color][/color]

In other words, if $executed is boolean true, it doesn't matter what
the string is that I'm comparing it to, it still makes the if statement
acts as if the statement is true?