php foreach循环，使用继续结果$ key始终为0 [重复]

Question

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• The 3 different equals 5 answers

<?php

$honorifics = array("None", "Miss", "Ms.", "Mrs.", "Mr.", " Mx", " Dr.", "Prof.", "Rabbi", "Reverend", "Imam");
?>

<?php foreach ($honorifics as $index => $honor){
        if ($index = 0) {
          continue;
        }
        echo ( $index );
}?>

prints out

00000000

why?

I saw that removing the continue fixes the problem, but thats not what I want. I wan't to understand what's going wrong.

how to fix?

</div>

Answer 1

if ($index = 0) {
    continue;
}

store 0 value to $index variable, what you want is if ($index == 0) or, better if (!$index)

In php (and other languages I assume) you can set a variable data in a condition, this is often not what you want ans should be avoided, but sometimes can be useful, take this example:

$len = $query->count()  // mysql query count()

if ($len) {
    // do stuff
}

// this can be shortened to

if ($len = $query->count()) {
    // do stuff if true
    echo $len;  // will echo the actual count()   
}

to avoid errors like this, I usually test my variables like this:

if (0 == $index)

this WILL throw an error if you miss your expression not on purpose :) but nowadays, when using IDE like phpstorm, netbeans or others, generally there is an inspection that warn you about that statement.

EDIT:

Here the inspection to enaable in PHPStorm:

And here the result: