What does .= mean in PHP?

Question

What is the difference between .= and = ? What is .= used for?

Example:

<?php
$file = fopen('WERK-tabelle.csv', 'r') or die('error');

$yml = '';
$keys = [
    blabla, code, php
];

while (($values = fgetcsv($file, 0, ';')) !== FALSE) {
    $yml .= "<br>";
    $arr = array_combine($keys, $values);
    foreach ($arr as $key => $value) {
        $yml .= "<br>{$key}{$value}\n";
    }
}

Also see [this question](https://stackoverflow.com/questions/3737139/reference-what-does-this-symbol-mean-in-php?rq=1) for a more complete list of PHP operators. — Phylogenesis, Jul 24 '17 at 12:39

score 5 · Accepted Answer · edited Jul 24 '17 at 12:41

5

.= is simply used to add something to the end of a string, without overwriting it.

Example 1 (without .=):

$myvar = "Hello";
$myvar = "Peter";
echo $myvar; //Will output "Peter"

Example 2 (With .=):

$myvar = "Hello";
$myvar .= "Peter";
echo $myvar; //Will output "HelloPeter" (concatenated string)

edited Jul 24 '17 at 12:41

BenRoob

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answered Jul 24 '17 at 12:38

Twinfriends

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Big Thanks to @BenRoob for the edit. For sure, there will be no space between Hello and Peter. – Twinfriends Jul 24 '17 at 12:42
Sorry for this hair splitting :) – BenRoob Jul 24 '17 at 12:45
1

@BenRoob Naaa its perfectly. I don't like not proper answers too and honestly its a quite big difference. – Twinfriends Jul 24 '17 at 12:46
Does the .= automatically add a whitespace at the beginning of the next string? – Denis Felst Jul 24 '17 at 12:46
@DenisFelst No. – GrumpyCrouton Jul 24 '17 at 12:47
1

@DenisFelst No, its exactly what Roob edited in my answer. I said that the output will be `Hello Peter` - whats not true. It will be `HelloPeter` without any whitespace. If you want the whitespace you have to do `$myvar .= " Peter";` or `$myvar = "Hello ";` – Twinfriends Jul 24 '17 at 12:48
Fine, understood it the other way round. Thank all of you !! – Denis Felst Jul 24 '17 at 13:06

What does .= mean in PHP?

1 Answers1