Variables & Data Types

PHP variables start with a $ sign and don't need a declared type — the type is determined by the value assigned to them.

Syntax

$name = "Ada";        // string
$age = 36;            // int
$height = 1.7;        // float
$isActive = true;     // bool
$tags = ["php", "web"]; // array
$nothing = null;      // null

Example

$score = 10;
echo $score;
$score = 20;
echo $score;

Expected output

1020

Use gettype($variable) to check a value's type at runtime, and var_dump($variable) to inspect both its type and value while debugging.

Common mistakes

• Forgetting the $ sigil — name = "Ada"; is a syntax error, since PHP needs $name.
• Expecting echo to add a newline automatically — it doesn't; the output above runs together on one line without an explicit \n.

Practice

Declare a variable called city holding your city's name, then print it.

$city = "Lagos";
echo $city;