chained if statements, best practise

[lajkonik86]

i have a set of three evaluations to make.

if the first one is true the second and third should no longer be evaluated

if the first is false, the second is true the third should not be evaluated

Don't know how you would call this, anyhow i didn't really like the idea of having many if, else statements stuck together. I decided to use a function as such:

    function levelchild($theorder) {
    if(!isset($theorder)) return 1;
    if(!strstr($theorder,'.')) return 2;
    $digits = strstr($theorder,'.'); 
    return (strlen($digits)-1)/2+1+1;
    }

Is this a good solution, should i have chose something else?

[NogDog]

Some people feel that a function should only have one return statement. Personally, I don't lose any sleep over it (and in fact have been known to use multiple returns more than a few times), but if you wanted to you could do:

function levelchild($theorder) {
    if(!isset($theorder)) {
        $result = 1;
    }
    elseif(!strstr($theorder,'.')) {
        $result = 2;
    }
    else {
        $digits = strstr($theorder,'.');
        $result = (strlen($digits)-1)/2+1+1;
    }
    return $result;
}

[lajkonik86]

wouldn't the function you specified output

2

instead of

1

when the input into the function is empty?

since the second if statement is also evaluated after the first one?

[NogDog]

In a chain of "if, elseif, elseif, . . . else" blocks, once an if or elseif evaluates as true, its code block is executed and then processing falls to the end of the entire chain, and an else block is only executed if the if is false as well as all intervening elseif's. So in the above example, if $theorder is evaluated as not set (which should never happen since it is a required parameter of the function), then $result would be set to 1 and processing would bypass the following elseif and else blocks, and then do the return statement.

[lajkonik86]

you are right, how did this detail ever pass by me :S
the difference never mattered to me before now 🙂

great, thanks!