Java Logical Operators in Conditions — Java interactive lesson

Logical Operators in Conditions

You can combine or reverse conditions using logical operators . These work together with if , else , and else if to build more complex decisions.

&& (AND) - all conditions must be true

-	(OR) - at least one condition must be true

! (NOT) - reverses a condition (true = false, false = true)

AND ( && )

Use AND ( && ) when both conditions must be true:

OR ( || )

Use OR ( || ) when at least one of the conditions can be true:

NOT ( ! )

Use NOT ( ! ) to reverse a condition:

Real-Life Example

In real programs, logical operators are often used for access control. For example, to get access to a system, there are specific requirements:

You must be logged in, and then you either need to be an admin, or have a high security clearance (level 1 or 2):

Example

boolean isLoggedIn = true;
boolean isAdmin = false;
int securityLevel = 3; // 1 = highest
if (isLoggedIn && (isAdmin || securityLevel <= 2)) {
  System.out.println("Access granted");
} else {
System.out.println("Access denied");
}
// Try changing securityLevel to test different outcomes: // // securityLevel 1 = Access granted // securityLevel 2 = Access granted // securityLevel 3 = Access denied // securityLevel 4 = Access denied // // If isAdmin = true, access is granted.