PHP Data Types
Understanding different types of data in PHP
🗂️ What are Data Types?
Data types specify what kind of data a variable can hold. PHP supports various data types including strings, integers, floats, booleans, arrays, objects, and more for different programming needs.
<?php
$text = "Hello"; // String
$number = 42; // Integer
$price = 19.99; // Float
$isActive = true; // Boolean
?>
Output:
String: Hello
Integer: 42
Float: 19.99
Boolean: true
PHP Data Types
String
A sequence of characters enclosed in quotes. Strings can contain letters, numbers, and special characters for text data.
<?php
$name = "John Doe";
$message = 'Hello World';
?>Integer
Whole numbers without decimal points. Integers can be positive, negative, or zero and are used for counting and calculations.
<?php
$age = 25;
$year = 2024;
?>Float
Numbers with decimal points, also called doubles. Floats are used for precise calculations involving fractions and monetary values.
<?php
$price = 99.99;
$pi = 3.14159;
?>Boolean
Represents true or false values. Booleans are essential for conditional logic and decision-making in programs.
<?php
$isLoggedIn = true;
$hasAccess = false;
?>Array
Stores multiple values in a single variable. Arrays can hold different data types and are accessed using numeric or string keys.
<?php
$colors = ["red", "blue"];
$person = ["name"=>"John"];
?>Object
Instances of classes that contain properties and methods. Objects enable object-oriented programming for complex data structures.
<?php
class Car {
public $color = "red";
}
?>NULL
Represents a variable with no value assigned. NULL is useful for indicating missing or undefined data in your programs.
<?php
$empty = NULL;
$notSet = null;
?>Resource
Special variables holding references to external resources like database connections or file handles for system operations.
<?php
$file = fopen("data.txt", "r");
// Resource type
?>🔹 String Data Type
Strings are sequences of characters:
<?php
// Single quotes
$name = 'Alice';
// Double quotes
$greeting = "Hello World";
// Multi-line string
$address = "123 Main Street
New York, NY 10001";
echo "Name: $name<br>";
echo "Greeting: $greeting<br>";
echo "Address: $address";
?>Output:
Name: Alice
Greeting: Hello World
Address: 123 Main Street
New York, NY 10001
🔹 Integer and Float
Numeric data types for calculations:
<?php
// Integer
$age = 30;
$year = 2024;
$negative = -15;
// Float
$price = 29.99;
$temperature = 98.6;
$pi = 3.14159;
echo "Age: $age<br>";
echo "Price: $price<br>";
echo "Pi: $pi";
?>Output:
Age: 30
Price: 29.99
Pi: 3.14159
🔹 Boolean Data Type
True or false values for logic:
<?php
$isActive = true;
$hasPermission = false;
echo "Is Active: " . ($isActive ? "Yes" : "No") . "<br>";
echo "Has Permission: " . ($hasPermission ? "Yes" : "No");
// Boolean in conditions
if ($isActive) {
echo "<br>User is active!";
}
?>Output:
Is Active: Yes
Has Permission: No
User is active!
🔹 Array Data Type
Store multiple values in one variable:
<?php
// Indexed array
$fruits = ["Apple", "Banana", "Orange"];
// Associative array
$person = [
"name" => "John",
"age" => 25,
"city" => "Boston"
];
echo "First fruit: " . $fruits[0] . "<br>";
echo "Name: " . $person["name"] . "<br>";
echo "Age: " . $person["age"];
?>Output:
First fruit: Apple
Name: John
Age: 25
🔹 Checking Data Types
Use var_dump() to check variable types:
<?php
$name = "Alice";
$age = 25;
$price = 19.99;
$isActive = true;
echo "String: ";
var_dump($name);
echo "<br>Integer: ";
var_dump($age);
echo "<br>Float: ";
var_dump($price);
echo "<br>Boolean: ";
var_dump($isActive);
?>Output:
String: string(5) "Alice"
Integer: int(25)
Float: float(19.99)
Boolean: bool(true)