Objective:
The primary objective of this lesson is to introduce learners to the fundamental concepts of variables and data types in PHP. By the end of this lesson, participants should be able to:
- Understand the concept of variables and their role in storing data.
- Declare variables in PHP and follow the naming conventions.
- Differentiate between common data types such as integers, strings, floats, and booleans.
- Assign values to variables and check their data types using appropriate functions.
1.1 Declaring Variables
1.1.1 Introduction to Variables
In PHP, a variable is a symbolic name for a value. This section will cover the basics of declaring variables, naming conventions, and assigning values.
<?php
$name = "John";
$age = 25;
$isStudent = true;
?>
1.1.2 Variable Naming Rules
Explore the rules for naming variables, including case-sensitivity, starting with a letter or underscore, and avoiding reserved words.
1.1.3 Variable Assignment
Learn how to assign values to variables using the assignment operator =.
1.2 Understanding Data Types
1.2.1 Integer
Understand the concept of integers as whole numbers without decimal points.
<?php
$quantity = 10;
$population = 5000000;
?>
1.2.2 String
Explore strings as sequences of characters enclosed in single or double quotes.
<?php
$name = "Alice";
$message = 'Hello, PHP!';
?>
1.2.3 Float
Learn about floats, representing numbers with decimal points.
<?php
$price = 19.99;
$pi = 3.14;
?>
1.2.4 Boolean
Introduce booleans as variables that represent true or false values.
<?php
$isStudent = true;
$hasCar = false;
?>
1.2.5 Checking Data Types
Use the gettype() function to check the data type of a variable.
<?php
$age = 25;
echo gettype($age); // Outputs: integer
?>
1.3 Practice Exercise
Apply the knowledge gained by writing a PHP script that declares variables for personal information, prints them along with their data types, and reinforces understanding.
<?php
// Declare variables
$myName = "YourName";
$myAge = 20;
$myHeight = 5.9;
$isStudent = true;
// Print out variables and their data types
echo "Name: $myName, Type: " . gettype($myName) . "<br>";
echo "Age: $myAge, Type: " . gettype($myAge) . "<br>";
echo "Height: $myHeight, Type: " . gettype($myHeight) . "<br>";
echo "Student: $isStudent, Type: " . gettype($isStudent) . "<br>";
?>