04 Java Fundamentals

Operators in Java

By Dummy for Dummies

Operators

Welcome back, fellow monkeys!

Monkeys aren't the brightest, but computers start off even dumber, they don't know anything until we tell them. Monkey can look at two bananas and just know which one's bigger. A computer can't. To make a computer capable of comparing things, we write code using operators.

Operators are the basic actions every piece of code relies on, things like:

Operators are what run these operations. Each one is a small decision or calculation, and stacking enough of them together is what makes a program actually do something.

1. Arithmetic Operators

These are the operators which perform basic mathematical operations. These operators are like calculator buttons.

public class Main {
    public static void main(String[] args) {
        int x = 10, y = 3;
        System.out.println(x + y);  // Prints 13
        System.out.println(x - y);  // Prints 7
        System.out.println(x * y);  // Prints 30
        System.out.println(x / y);  // Prints 3 (integer division)
        System.out.println(x % y);  // Prints 1 (remainder)
    }
}

2. Assignment Operator ( = )

This is a single operator that assigns a certain value to a variable. = tells the computer to take what is on the right side and store it in the left side. With few modifications it can be used in many ways:

• Direct Assignment: int a = 5; puts 5 in a
• Update Assignment: a = a + 2; takes a (5), adds 2, stores back into a (now 7)
• Shortcut Assignment: a += 3; same as a = a + 3;
• Shortcut Multiplication: a *= 2; same as a = a * 2;

3. Relational Operators (For Comparison)

These compare two values with each other and give a boolean which is either true or false.

public class Main {
    public static void main(String[] args) {
        int a = 5, b = 7;
        System.out.println(a == b);  // false
        System.out.println(a != b);  // true
        System.out.println(a > b);   // false
        System.out.println(a < b);   // true
        System.out.println(a >= 5); // true
    }
}

4. Logical Operators

These operators combine boolean values and work on them. They are like the logic gates we studied in 10th standard. There are three logical operators:

public class Main {
    public static void main(String[] args) {
        System.out.println(true && true);   // true
        System.out.println(true && false);  // false
        System.out.println(false && false); // false
        System.out.println(true || true);    // true
        System.out.println(true || false);   // true
        System.out.println(false || false);  // false
        System.out.println(!true);         // false
        System.out.println(!false);        // true
    }
}

5. Unary Operators

These are shortcuts for mathematical operations of increasing a number by one or decreasing by one. There are two Unary Operators:

• ++ → Called Increment. Increases a number by 1
• -- → Called Decrement. Decreases a number by 1

But this is not the end, the unary operators can be used in 2 different ways which perform the same action through different methods. These are post and pre methods.

• Pre-Increment ++x → First add one more banana, later do whatever you want
• Post-Increment x++ → First do whatever you want, later add one more banana
• Pre-Decrement --x → First eat a banana, later do whatever you want
• Post-Decrement x-- → First do whatever you want, later eat a banana

public class Main {
    public static void main(String[] args) {
        int a = 5, b = 7, c = 10, d = 12;

        System.out.println(++a);  // Prints 6 (increment first, then print)
        System.out.println(b++);  // Prints 7 (print first, then increment)
        System.out.println(--c);  // Prints 9 (decrement first, then print)
        System.out.println(d--);  // Prints 12 (print first, then decrement)

        // Final values after all operations
        System.out.println(a);  // 6
        System.out.println(b);  // 8
        System.out.println(c);  // 9
        System.out.println(d);  // 11
    }
}

Extra: Comments

The computer throws an error when it hits something it doesn't recognize. Comments let you write notes in your code that Java skips over entirely. There are two kinds, single line and multi line.

// Monkey likes Bananas

The double forward slash tells the computer "ignore everything after this point, on this line."

/*  
  Monkey likes apples too  
  But hates pineapples  
*/

Closing

That's it for operators in Java. Operators are like small brain cells for programming. They help computers compare, calculate, assign, and make logical decisions. Without them, our programs would just sit there like a monkey staring at bananas. In the next blog, we will understand Input in Java.