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phparraysdefinition

PHP empty array definition with starting or ending comma

So I've come accross these on PHP8 code from my office (simplified) :

[, $x] = $y;

I also saw the other way

[$x, ] = $y;

What would these do? If I do that in a sandbox and assign random values to $y beforehand, I don't get anything for $x. I know that it is not badcode, as PHPStorm valids it.

I've tried searching for it, but every search engines including Stackoverflow will ignore commas or [], so I can't get my answer.

Solution 
  • $array = [10, 20, 30];

[$x, ] = $array;

echo $x;  // Output: 10

[, $x] = $array;

echo $x;  // Output: 20

[2 => $x] = $array;

echo $x;  // Output: 30

    It's called array destructuring.