PHP boolean 对/错？

Question

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)
...

Answer 1

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.

Answer 2

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
}

Answer 3

You could do like this

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

Answer 4

您可以使用if($result == TRUE)但这样就像if($result)就足够了。

Answer 5

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...

Answer 6

Double check you have gettype($result) == bool and NOT string.