我无法在PHP中获得返回值[关闭]

Question

I can't get the return value! The Output appears 'ERROR'.

$c = new List();
$result = $c->create();

if( $result == "a"){
   echo("A");                   
}else if($result == "b"){
   echo("B");
}else{
   echo("ERROR");
}

class List{

    function create(){

       // $rVal = ...

       if($rVal == 1){
           return "a";
       }else if($rVal == 2){
           return "b";
       }
    }
}

when I change return to echo, the output appears 'aERROR'. I don't understand. create function works but the return value is not true. Can anyone help me please? Sorry for my bad English

Answer 1

If the code below is correct, then you are not setting $rVal. The assignment seems commented out:

class List{

    function create(){

       // $rVal = ...

       if($rVal == 1){
           return "a";
       }else if($rVal == 2){
           return "b";
       }
    }
}

So, nothing (null) will be returned by create() call... which is interpreted as false.