在php函数内返回后需要退出吗？

Question

<?php

function testEnd($x) {
    if ( ctype_digit($x) ) {
        if ( $x == 24 ) {
            return true;
            exit;
        } else {
            return false;
                 exit;
        }
    } else {
        echo 'If its not a digit, you\'ll see me.';
        return false;
        exit;
    }
}

$a = '2';

if ( testEnd($a) ) {
    echo 'This is a digit';
} else {
    echo 'No digit found';
}
?>

Is exit needed along with return when using them inside a php function? In this case, if anything evaluated to false, i'd like to end there and exit.

Answer 1

No it's not needed. When you return from a function then any code after that does not execute. if at all it did execute, your could would then stop dead there and not go back to calling function either. That exit should go

According to PHP Manual

If called from within a function, the return statement immediately ends execution of the current function, and returns its argument as the value of the function call. return will also end the execution of an eval() statement or script file.

Whereas, exit , according to PHP Manual

Terminates execution of the script.

So if your exit was really executing, it would stop all the execution right there

EDIT

Just put up a small example to demonstrate what exit does. Let's say you have a function and you want to simply display its return value. Then try this

<?php

function test($i)
{
    if($i==5)
    {
        return "Five";
    }
    else
    {
        exit;
    }
}


echo "Start<br>";
echo "test(5) response:";
echo test(5);

echo "<br>test(4) response:";
echo test(4); 

/*No Code below this line will execute now. You wont see the following `End` message.  If you comment this line then you will see end message as well. That is because of the use of exit*/


echo "<br>End<br>";


?>