Nested if

Example

You can put an if inside another one when a second decision depends on the first.

public class Main {
    public static void main(String[] args) {
        boolean isLoggedIn = true;
        boolean isAdmin = false;
        if (isLoggedIn) {
            System.out.println("Welcome back!");
            if (isAdmin) {
                System.out.println("Opening admin dashboard");
            } else {
                System.out.println("Opening user home page");
            }
        } else {
            System.out.println("Please log in");
        }
    }
}

Output

Welcome back!
Opening user home page

Example

public class Main {
    public static void main(String[] args) {
        int year = 2024;
        // leap year: divisible by 4, but not by 100 unless also by 400
        boolean leap = (year % 4 == 0 && year % 100 != 0) || year % 400 == 0;
        System.out.println(year + " leap year? " + leap);
        System.out.println(1900 + " leap year? " + ((1900 % 4 == 0 && 1900 % 100 != 0) || 1900 % 400 == 0));
    }
}

Output

2024 leap year? true
1900 leap year? false