Operators

Welcome to PHP Operators

Imagine you're building an online shopping application.

When a customer places an order, your application needs to:

• Calculate the total price.
• Apply discounts.
• Compare payment amounts.
• Check whether a user is logged in.
• Verify stock availability.

How does PHP perform all these operations?

The answer is Operators.

Operators are symbols that tell PHP to perform a specific task, such as adding numbers, comparing values, or making logical decisions.

Without operators, your application would not be able to calculate prices, validate login credentials, or process business rules.

What are Operators?

An Operator is a special symbol that performs an operation on one or more values.

Think of operators as instructions.

For example:

• Add two numbers
• Compare two values
• Assign a value
• Check multiple conditions
• Join two strings

Operators are used in almost every PHP program.

Why Do We Need Operators?

Imagine a food delivery application.

The application needs to answer questions like:

• Is the customer eligible for free delivery?
• Is the order amount greater than ₹500?
• Is the payment successful?
• Should GST be added?
• How much is the final bill?

These calculations and decisions are made using operators.

Types of Operators in PHP

PHP provides several categories of operators.

We'll learn each category in dedicated lessons.

Today, you'll understand the overall idea behind operators.

Arithmetic Operators Example

Arithmetic operators perform mathematical calculations.

<?php

$price = 1000;
$gst = 180;

$total = $price + $gst;

echo $total;

?>

Output

1180

Here, the + operator adds two values.

Comparison Operator Example

Comparison operators help PHP compare values.

<?php

$age = 20;

var_dump($age >= 18);

?>

Output

bool(true)

PHP checks whether the value is greater than or equal to 18.

Logical Operator Example

Suppose a banking application allows loans only if:

• Customer age is above 21.
• Monthly salary is above ₹50,000.

<?php

$age = 28;
$salary = 70000;

if ($age >= 21 && $salary >= 50000) {
    echo "Loan Approved";
}

?>

The && operator ensures both conditions are true.

Real-World Example

Imagine you're building an online shopping cart.

<?php

$productPrice = 2500;
$quantity = 2;
$discount = 500;

$total = ($productPrice * $quantity) - $discount;

echo "Final Amount: ₹" . $total;

?>

Output

Final Amount: ₹4500

Here, multiple operators work together to calculate the final bill.

Best Practices

• Use parentheses to make calculations easier to read.
• Keep expressions simple and readable.
• Use meaningful variable names.
• Avoid combining too many operators in one statement.
• Test complex conditions before deploying your application.

Common Mistakes

Mixing Assignment (=) and Comparison (==)

Incorrect

if ($age = 18)

Correct

if ($age == 18)

Writing Complex Conditions

Avoid long, unreadable expressions. Break complex logic into smaller variables.

Ignoring Operator Precedence

Use parentheses whenever calculations become difficult to understand.

Hands-on Exercise

Task: Create variables for Product Price, Quantity, and Discount. Calculate the final amount.

Challenge: Create an employee bonus calculator with Salary and Bonus Percentage. Calculate the total salary after adding the bonus.

<?php

// TODO: Task
$productPrice = 2500;
$quantity = 2;
$discount = 500;
// $total = ...

// TODO: Challenge — bonus calculator
?>

Summary

• Operators perform calculations, comparisons, and logical decisions.
• PHP provides different operator categories for different tasks.
• Operators are essential for building dynamic applications.
• Arithmetic operators calculate values.
• Comparison and logical operators help applications make decisions.

Key Takeaways

• Operators make PHP programs interactive and dynamic.
• Different operators solve different problems.
• Keep expressions simple and readable.
• Always understand the difference between assignment and comparison.
• Operator knowledge is fundamental to every PHP application.

Interview Questions & Professional Answers

$total = 100 + 50;

$age = 18;     // Assignment

$age == 18;    // Comparison

$result = 10 + 5 * 2;  // Result: 20

$result = (10 + 5) * 2;  // Result: 30

What's Next?

Now that you understand what operators are and why they are important, it's time to explore them one category at a time.

In the next lesson, Type Casting, you'll learn how PHP converts values between data types — a skill you'll use constantly alongside operators in real applications.