PHP Variables

In PHP, variables are used to store data like strings, numbers, arrays, and more. All variables start with a $ sign followed by the variable name.

Rules to Declare PHP Variables:

• Variable names start with $ (dollar sign)
• Must begin with a letter or underscore (_)
• Cannot start with a number
• Can contain only letters, numbers, and underscores
• Variable names are case-sensitive ($name and $Name are different)

<?php
  $name = "John";
  $age = 25;
  echo "My name is $name and I am $age years old.";
?>

<?php
  $x = 10;
  echo $x;   // Output: 10
  echo $X;   // Error: Undefined variable
?>

<?php
  $user_name = "livecoder";
  echo $user_name;
?>

<?php
  $color = "Red";
  echo $color;
  $color = "Blue"; // Reassigning
  echo $color;
?>