使用三元和冒号进行循环

Question

This is from a tutorial for php, I cant understand the use of the ternary ? And the use of the colon : Can you please explain to me the use of the colon in here thanks I tried to read the tutorial and php reference but couldn't understand it

This code will print a side way pyramid

 for ($row = 1; $row <= 5; $row++)
  {
      for ($col = 1; $col <= ($row > 3 ? 6 - $row : $row); $col++)
      {
          echo '*';
      }

      echo "<br>";
  }

Answer 1

This is the same as the following code:

for ($row = 1; $row <= 5; $row++)
{
    if ($row > 3)
        $max = 6 - $%row;
    else 
        $max = $row;

    for ($col = 1; $col <= $max; $col++)
    {
        echo '*';
    }

    echo "<br>";
}

The colon is part of the ternary operator:

A ? B : C

equals to

if (A) then B else C

For more information please check the documentation on the ternary (?:) operator.