Nested if Statements in Java

Introduction

In Java, sometimes a single condition isn’t enough to determine the right path for your code. That’s where nested if statements come into play. These statements allow you to write more detailed and layered conditions by placing one if statement inside another.

This blog explores how nested if statements in Java work and when to use them effectively.

What is a Nested if Statement?

A nested if statement is simply an if condition that exists within another if or else block. It allows for greater control and precision when handling complex logic where multiple conditions need to be true before executing a block of code.

Syntax of Nested if Statement

if (condition1) {
    if (condition2) {
        // executes if both condition1 and condition2 are true
    }
}

Basic Example

public class NestedIfExample {
    public static void main(String[] args) {
        int number = 25;

        if (number > 0) {
            if (number % 5 == 0) {
                System.out.println("Positive number and divisible by 5.");
            }
        }
    }
}

Output:

Positive number and divisible by 5.

Why Use Nested if Statements?

Nested if statements are useful when:

• You need to check a secondary condition only if a primary condition is true.
• You want to organize complex logic in a structured way.
• You’re validating multiple inputs or criteria before proceeding.

Example: Checking User Role and Access

Let’s say you’re building a system where a user needs to be both an admin and logged in to access a dashboard.

String userRole = "admin";
boolean isLoggedIn = true;

if (isLoggedIn) {
    if (userRole.equals("admin")) {
        System.out.println("Access granted to admin dashboard.");
    } else {
        System.out.println("Access denied. Admin privileges required.");
    }
} else {
    System.out.println("Please log in first.");
}

Nested if vs. Logical AND (&&)

Sometimes, nested if statements can be replaced with a single if using a logical AND operator. For example:

// Using nested if
if (x > 0) {
    if (x < 100) {
        System.out.println("x is between 1 and 99");
    }
}

// Using &&
if (x > 0 && x < 100) {
    System.out.println("x is between 1 and 99");
}

Both approaches work, but nested ifs may provide better clarity when additional logic or conditions are added later.

Tips for Writing Nested if Statements

• Avoid deeply nested conditions as they reduce readability. Refactor when possible.
• Always use curly braces {} to prevent logical errors.
• Use comments or meaningful variable names to improve understanding.

Conclusion

Nested if statements in Java are a powerful feature for handling complex decision-making. They allow you to test multiple layers of logic in a clean and organized manner. However, be mindful of readability and consider alternatives like logical operators or switch statements for certain use cases.