PHP infinite for(;;) loop

Question

Hi so i just frequently started doing PHP at school and now I have this project in school and when my code gets to this part:

for ($i=0; $i<=sizeof($kentat_taulukkona); +$i) {
    echo $i;
    if($i=1) {
        $a = "=".$arvot_taulukkona[$i];
        $aa = $kentat_taulukkona[$i];
    } else if($i=2) {
        $b = "=".$arvot_taulukkona[$i];
        $ab = ", ".$kentat_taulukkona[$i];
    } else if($i=3) {
        $c = "=".$arvot_taulukkona[$i];
        $ac = ", ".$kentat_taulukkona[$i];
    } else if($i=4) {
        $d = "=".$arvot_taulukkona[$i];
        $ad = ", ".$kentat_taulukkona[$i];
    } else if($i=5) {
        $e = "=".$arvot_taulukkona[$i];
        $ae = ", ".$kentat_taulukkona[$i];
    } else if($i=6) {
        $f = "=".$arvot_taulukkona[$i];
        $af = ", ".$kentat_taulukkona[$i];
        break;
    }
}

it becomes an infinite loop. With that echo i found out it first echoes one 0 and after that number 1 till the end of the world.It might be just a typo what I'm missing or have I understood something wrong since to my knowledge this should work?

on top of what John says, $i=1 youre not comparing (==), you're setting. — castis
– castis, Commented May 9, 2017 at 18:14
Dynamic loop by sizeof($kentat_taulukkona), but a break at the 6th iteration. Strange... — Sterling Beason
– Sterling Beason, Commented May 9, 2017 at 18:34
Instead of creating all these variable, you should use arrays. To improve your code you can also search about: foreach, range, and if you are hot: array_map — Casimir et Hippolyte
– Casimir et Hippolyte, Commented May 9, 2017 at 18:43
Yeah Sterling i did it out of desperation since I couldnt understand whats wrong i tried all kinds of dumb stuff, there is also only one '+' because before i took one off it always repeated number 2 and i thought i had misunderstood it and that with '++' it would always add two. — Tired Chibi
– Tired Chibi, Commented May 9, 2017 at 18:46

Community · Accepted Answer · 2017-05-23 11:47:04Z

2

You need to use the comparison operator like == and not the assignment operator =

So your code should be:

if($i==1) {
    $a = "=".$arvot_taulukkona[$i];
    $aa = $kentat_taulukkona[$i];
}else if($i==2) {
    $b = "=".$arvot_taulukkona[$i];
    $ab = ", ".$kentat_taulukkona[$i];
} else if($i==3) {
    $c = "=".$arvot_taulukkona[$i];
    $ac = ", ".$kentat_taulukkona[$i];
} else if($i==4) {
    $d = "=".$arvot_taulukkona[$i];
    $ad = ", ".$kentat_taulukkona[$i];
} else if($i==5) {
    $e = "=".$arvot_taulukkona[$i];
    $ae = ", ".$kentat_taulukkona[$i];
}else if($i==6) {
    $f = "=".$arvot_taulukkona[$i];
    $af = ", ".$kentat_taulukkona[$i];
    break;

Also if you want to keep increasing value of $i by use $i++ thus making your code look like:

for ($i=0; $i<=sizeof($kentat_taulukkona); $i++) {
    echo $i;
    if($i==1) {
        $a = "=".$arvot_taulukkona[$i];
        $aa = $kentat_taulukkona[$i];
    } else if($i==2) {
        $b = "=".$arvot_taulukkona[$i];
        $ab = ", ".$kentat_taulukkona[$i];
    } else if($i==3) {
        $c = "=".$arvot_taulukkona[$i];
        $ac = ", ".$kentat_taulukkona[$i];
    } else if($i==4) {
        $d = "=".$arvot_taulukkona[$i];
        $ad = ", ".$kentat_taulukkona[$i];
    } else if($i==5) {
        $e = "=".$arvot_taulukkona[$i];
        $ae = ", ".$kentat_taulukkona[$i];
    } else if($i==6) {
        $f = "=".$arvot_taulukkona[$i];
        $af = ", ".$kentat_taulukkona[$i];
        break;
    }
}

UPDATE as suggested by @SterlingBeason plase consider using the prefix ++$i or the postfix $i++ operator according to your needs. To read more about the operators in detail check the answer at SO What's the difference between ++$i and $i++ in PHP?

edited May 23, 2017 at 11:47

CommunityBot

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answered May 9, 2017 at 18:16

Shakti Phartiyal

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4 Comments

Jeremy Harris Over a year ago

And also do what Sterling suggested with ++$i

Sterling Beason Over a year ago

@ShaktiPhartiyal prepending and appending the "++" to an int variable do different things. The ++ need to prepend the $i variable for the first IF condition to be met as true. ($i==1)

Shakti Phartiyal Over a year ago

@SterlingBeason I agree with you the operation of prefix and postfix operatiors is different. Not sure whether the OP wants to use which one.. But surely will add it in my answer..

Tired Chibi Over a year ago

Thank you for your answer, i can't believe i did that, and on top of it didn't notice it. I will keep it as ++$i since I'm not too sure if understand the difference, and it seems to work either way. Thank you.

Sterling Beason · Accepted Answer · 2017-05-09 18:16:37Z

0

Change the first line of the loop to this:

for ($i=0; $i<=sizeof($kentat_taulukkona); ++$i) { ....

And your IF statements needs to be changed to this (double equal sign to test equality):

if($i==1) {...

answered May 9, 2017 at 18:16

Sterling Beason

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