and condition in php if code example

Example 1: php if

<?php
if ($a > $b) {
  echo "a is bigger than b";
  $b = $a;
}
?>

Example 2: php if

<?php
if ($a > $b)
  echo "a is bigger than b";
?>

Example 3: php multi condition if

if($var == "abc" || $var == "def" || ...)
{
    echo "true";
}

Example 4: if statement php

if (condition) {
  expression
}