Java Booleans

Working with true and false values in Java

✅ What are Java Booleans?

Java Booleans represent true or false values. They are essential for making decisions in your programs and controlling program flow with conditions and logical operations. 


// Boolean variables in Java
boolean isJavaFun = true;
boolean isFishTasty = false;
System.out.println("Java is fun: " + isJavaFun);
System.out.println("Fish is tasty: " + isFishTasty);

Output:

Java is fun: true

Fish is tasty: false

Boolean Operations

🔍

Comparison

Compare values to get boolean results 

boolean result = 5 > 3; // true
🔗

Logical AND

Both conditions must be true 

boolean result = true && false; // false
🔀

Logical OR

At least one condition must be true 

boolean result = true || false; // true
❗

Logical NOT

Reverse the boolean value 

boolean result = !true; // false

🔹 Comparison Operators

Use comparison operators to create boolean expressions: 

public class BooleanComparison {
    public static void main(String[] args) {
        int x = 10;
        int y = 5;
        
        // Comparison operators
        boolean equal = (x == y);        // false (10 == 5)
        boolean notEqual = (x != y);     // true (10 != 5)
        boolean greater = (x > y);       // true (10 > 5)
        boolean less = (x < y);          // false (10 < 5)
        boolean greaterEqual = (x >= y); // true (10 >= 5)
        boolean lessEqual = (x <= y);    // false (10 <= 5)
        
        System.out.println("x equals y: " + equal);
        System.out.println("x greater than y: " + greater);
    }
}

Output:

x equals y: false

x greater than y: true

🔹 Logical Operators

Combine multiple boolean expressions: 

public class LogicalOperators {
    public static void main(String[] args) {
        int age = 25;
        boolean hasLicense = true;
        
        // Logical AND (&&) - both must be true
        boolean canDrive = (age >= 18) && hasLicense;
        
        // Logical OR (||) - at least one must be true
        boolean isAdult = (age >= 18) || (age >= 21);
        
        // Logical NOT (!) - reverse the value
        boolean isMinor = !(age >= 18);
        
        System.out.println("Can drive: " + canDrive);
        System.out.println("Is minor: " + isMinor);
    }
}

Output:

Can drive: true

Is minor: false

🔹 Boolean in Real Applications

Practical example using booleans for decision making: 

public class BooleanExample {
    public static void main(String[] args) {
        int temperature = 25;
        boolean isSunny = true;
        boolean hasUmbrella = false;
        
        // Decision making with booleans
        boolean goodWeather = (temperature > 20) && isSunny;
        boolean needUmbrella = !isSunny && !hasUmbrella;
        
        System.out.println("Good weather for picnic: " + goodWeather);
        System.out.println("Need to buy umbrella: " + needUmbrella);
        
        // Using boolean in conditions
        if (goodWeather) {
            System.out.println("Let's go for a picnic!");
        }
    }
}

Output:

Good weather for picnic: true

Need to buy umbrella: false

Let's go for a picnic!

🧠 Test Your Knowledge

What is the result of: true && false?