Foreach loop, but for first key do something else

Question

Sorry if this is confusing. It's tough for me to put into words having beginner knowledge of PHP.

I'm using the following foreach loop:

foreach ($_POST['technologies'] as $technologies){
    echo ", " . $technologies;
}

Which produces:

, First, Second, Third

What I want:

First, Second, Third

All I need is for the loop to skip the echo ", " for the first key. How can I accomplish that?

Answer 1

You can pull out the indices of each array item using => and not print a comma for the first item:

foreach ($_POST['technologies'] as $i => $technologies) {
    if ($i > 0) {
        echo ", ";
    }

    echo $technologies;
}

Or, even easier, you can use implode($glue, $pieces), which "returns a string containing a string representation of all the array elements in the same order, with the glue string between each element":

echo implode(", ", $_POST['technologies']);

Answer 2

For general case of doing something in every but first iteration of foreach loop:

$first = true;
foreach ($_POST['technologies'] as $technologies){
    if(!$first) {
      echo ", ";
    } else {
      $first = false;
    }
    echo $technologies;
}

but implode() is best way to deal with this specific problem of yours:

echo implode(", ", $_POST['technologies']);

Answer 3

You need some kind of a flag:

$i = 1;
foreach ($_POST['technologies'] as $technologies){
  if($i > 1){
    echo ", " . $technologies;
  } else {
    echo $technologies;
  }
  $i++;
}