In an IF statement in PHP with OR, how to track which condition evaluated false?

for example, in PHP code like this:

if($this->function1() && $this->function2())
{
  //everything is alright
}
else
{
  //function1 or function2 returned false
  //whodunnit?
}

Is there a language construct or something that can help me find out the culprit in the else block? I don't want to have to run the conditions once again, just to find out what went wrong.

Please bear with my pseudo-code. My actual code will look totally out开发者_JAVA百科-of-context here... and I'm using CodeIgniter, by the way.

---

if($this->function1()) {
    if($this->function2()) {
        // both worked
    } else {
        // function1 returned a true value
        // function2 returned a false value
    }
} else {
    // function1 returned a false value
    // (you could optionally call $this->function2() here)
}

or, if you always want to run both functions:

$result1 = $this->function1();
$result2 = $this->function2();
if($result1 && $result2) {
    // everything is okay
} else {
    // look at the results to figure out what to do
}

or, if you want to do the first but without 2 levels of indentation:

if(!$this->function1()) {
    // function1 returned false
    // (you can call $this->function2() here if you want)
} elseif (!$this->function2()) {
    // function2 returned false
} else {
    // everything is okay
}

---

I want to use the name of the function that caused the error.

This is somewhat ugly. I wouldn't use it (= "for this purpose").
Also I'm making this CW to eschew the downvotes.

 if ($this->function1($failed="func1") && $this->function2(.., $failed="func2")) {
    ...
 }
 else {
    print $failed;

This syntactic workaround necessitates that you can fill up the methods parameters with the required number and pass the fake $failed parameter in an unused spot. It in fact just adds this variable to the local variable scope.

You could redesign this if-statement more clumsily with more && ands and () parens to the same effect. This is just somewhat compacter. Yet I'm not sure if I understand why you would want a string with the failed function name, not just a boolean, or what's up with the ifphobia.

---

Most trivial solution: store the results of both functions in variables and check them in your if-condition.

---

try{
    functionA();
    functionB();
}catch(YourExceptionType $e){
    //use $e to know what, where, and why it happened
}

That's what I would do

and if you are not throwing exceptions you may use "or", because when function is true then the second part of the or will never be run:

functionA() or somethingWentWrong();
functionB() or somethingWentWrong();

but I still recoment try/catch

---

You can use temporary variables in the if itself:

if ($f1=$this->function1() and $f2=$this->function2()) {

Then later check them.

Note that I replaced && with and to avoid extra parenthesis (the and has lower precedence than the assignment).