The Problem of Curly Braces in Loops in PHP

Although you can omit curly braces in loops, I highly discourage doing so, as such code often leads to errors.

Let's look at an example. Suppose we have the following code:

php<?php
  for ($i = 0; $i <= 9; $i++)
    echo $i; // will output numbers from 0 to 9
?>

I will make a small correction to the code above (find which one) - and it will stop working:

php<?php
  for ($i = 0; $i <= 9; $i++);
    echo $i; // will output 10
?>

So, what did I fix?

The problem arose because I put a semicolon after the bracket ) of the loop. In this case, we get a so-called loop without a body: it will simply spin inside, and the next line will no longer refer to it. Therefore, to avoid problems, I always recommend using curly braces in loops.

php<?php
  $arr = [1, 2, 3, 4, 5];
  
  foreach ($arr as $elem);
    echo $elem;
?>