PHP布尔值TRUE / FALSE？

I can't figure this out.

If I type:

function myfunction(){
    ......
    if ...
        return TRUE;
    if ...
        return FALSE;
}

Why can't I use it like this:

$result = myfunction();
if ($result == TRUE)
...
if ($result == FALSE)
...

Or do I have to use:

$result = myfunction();
if ($result == 1)
...
if ($result == 0)
...

Or this:

$result = myfunction();
if ($result)
...
if (!$result)
...

I don't fully understand your question, but you can use any of the examples you provided, with the following caveats:

If you say if (a == TRUE) (or, since the comparison to true is redundant, simply if (a)), you must understand that PHP will evaluate several things as true: 1, 2, 987, "hello", etc.; They are all "truey" values. This is rarely an issue, but you should understand it.

However, if the function can return more than true or false, you may be interested in using ===. === does compare the type of the variables: "a" == true is true, but "a" === true is false.

if($variable) 
//something when truw
else 
//something else when false

Remember that the value -1 is considered TRUE, like any other non-zero (whether negative or positive) number. FALSE would be 0 obv...

You could do like this

$result = myfunction();
if ($result === TRUE)
...
if ($result === FALSE)
...

You can use if($result == TRUE) but that's an overkill as if($result) is enough.

If you dont need to use the result variable $result furthermore, I would do the following shortest version:

if (myfunction()) {
    // something when true
} else {
    // something else when false
}