Nested If - Else

Part of the Fundamentals section of Coddy's Java journey — lesson 32 of 73.

We can nest if-else if-else statements within each other. This allows us to create hierarchical decision-making structures.

Keep in mind that deeply nested if statements can make code harder to read and maintain.

For example:

if (age > 18) {
    if (hasLicense) {
        System.out.println("You can drive");
    } else {
        System.out.println("Get a license first");
    }
} else {
    System.out.println("Too young to drive");
}

It can be infinitely nested:

if (condition1) {
	if (condition2) {
		if (condition3) {
		    // runs only when condition1, condition2 and condition3 are all true
		    ...
		}
	}
}

Challenge

Beginner

Create a program that checks if someone can ride a rollercoaster. The requirements are:

Must be at least 12 years old
Must be taller than 150cm
If they meet both requirements but are under 15, they need adult supervision

Print exactly these messages for each case:

If too young: Sorry, you're too young
If not tall enough: Sorry, you're not tall enough
If under 15 and no adult: Sorry, you need an adult with you
If under 15 with adult: You can ride with adult supervision!
If 15 or older and tall enough: You can ride by yourself!

Cheat sheet

You can nest if-else if-else statements within each other to create hierarchical decision-making structures:

if (age > 18) {
    if (hasLicense) {
        System.out.println("You can drive");
    } else {
        System.out.println("Get a license first");
    }
} else {
    System.out.println("Too young to drive");
}

Nesting can be done infinitely:

if (condition1) {
    if (condition2) {
        if (condition3) {
            // if condition1, condition2 and condition3 are true
            ...
        }
    }
}

Note: Deeply nested if statements can make code harder to read and maintain.

Try it yourself

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int age = scanner.nextInt(); // Don't change this line
        int height = scanner.nextInt(); // Don't change this line
        boolean hasAdult = scanner.nextBoolean(); // Don't change this line

        // Write your code below
        
        scanner.close();
    }
}