PHP Concatenation – Comma (,) vs Dot (.)

Comma isn’t a concatenator. it use for printing or rather echoing a list of variable, string and numbers similar to how it is used in English. While dot joins two strings together to make one longer string.

Take note: comma only work when using the echo language construct and you can’t return a comma delimited variable.

Examples

Let’s see some code example.

• ?

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  <?php $a = 'i am'; $b = ' boy'; echo $a, $b;

  ?

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  <?php $a = 'i am'; $b = ' boy'; $c = $a . $b; echo $c;

  ?

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  <?php $a = 'i am'; $b = ' boy'; echo $a . $b;

  Result: i am boy
• ?

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  <?php $a = 'i am'; $b = ' boy'; print($a, $b);

  ?

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  <?php $a = 'i am'; $b = ' boy'; $c = $a, $b;

  ?

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  <?php $a = 'i am'; $b = ' boy'; return $a , $b;

  Result: Parse error: syntax error, unexpected ‘,’ in C:\xampp\htdocs\index.php on line 4

It is worth noting that when using echo, delimiting string with comma is faster than dot.