Example:

package octopuscodes.com.demo;

import java.util.Scanner;

public class Demo {

	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		System.out.print("a: ");
		double a = scanner.nextDouble();

		double area = a * a;
		double perimeter = a * 4;

		System.out.println("Area : " + area);
		System.out.println("Perimeter : " + perimeter);

	}

}

Output:

a: 5
Area : 25.0
Perimeter : 20.0

The post Write a Java program to print the area and perimeter of a square appeared first on OctopusCodes.

Example:

package octopuscodes.com.demo;

import java.util.Scanner;

public class Demo {

	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		System.out.print("a: ");
		double a = scanner.nextDouble();
		System.out.print("b: ");
		double b = scanner.nextDouble();

		double area = a * b;
		double perimeter = (a + b) * 2;

		System.out.println("Area : " + area);
		System.out.println("Perimeter : " + perimeter);

	}

}

Output:

a: 3
b: 10
Area : 30.0
Perimeter : 26.0

The post Write a Java program to print the area and perimeter of a rectangle appeared first on OctopusCodes.

Example:

package octopuscodes.com.demo;

import java.util.Scanner;

public class Demo {

	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		System.out.print("Radius: ");
		double radius = scanner.nextDouble();
		double area = Math.PI * radius * radius;
		double perimeter = 2 * Math.PI * radius;
		System.out.println("Area : " + area);
		System.out.println("Perimeter : " + perimeter);

	}

}

Output:

Radius: 4
Area : 50.26548245743669
Perimeter : 25.132741228718345

The post Write a Java program to print the area and perimeter of a circle appeared first on OctopusCodes.

Example:

package octopuscodes.com.demo;

import java.util.Scanner;

public class Demo {

	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		System.out.print("Celsius: ");
		double celsius = scanner.nextDouble();
		double fahrenheit = celsius * 1.8 + 32;
		System.out.println("Fahrenheit: " + fahrenheit);

	}

}

Output:

Celsius: 100
Fahrenheit: 212.0

The post Write a Java program to convert Celsius into Fahrenheit appeared first on OctopusCodes.

Example:

package octopuscodes.com.demo;

import java.util.Scanner;

public class Demo {

	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		System.out.print("Fahrenheit: ");
		double fahrenheit = scanner.nextDouble();
		double celsius = (fahrenheit - 32) / 1.8;
		System.out.println("Celsius: " + celsius);

	}

}

Output:

Fahrenheit: 212
Celsius: 100.0

The post Write a Java program to convert Fahrenheit into Celsius appeared first on OctopusCodes.

• Write a Java program to convert Fahrenheit into Celsius.
• Write a Java program to convert Celsius into Fahrenheit.
• Write a Java program to print the area and perimeter of a circle.
• Write a Java program to print the area and perimeter of a rectangle.
• Write a Java program to print the area and perimeter of a square.

The post Java Operators with Real Life Examples appeared first on OctopusCodes.

1. (=) Operator

This operator is used to assign the value on the right to the variable on the left.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int a = 10;
		System.out.println("a: " + a);
		
		double b, c, d, e;
		b = c = d = e = 4.5;		
		System.out.println("b: " + b);
		System.out.println("c: " + c);
		System.out.println("d: " + d);
		System.out.println("e: " + e);
		
		double f = b + c;
		System.out.println("f: " + f);
	}

}

Output:

a: 10
b: 4.5
c: 4.5
d: 4.5
e: 4.5
f: 9.0

2. (+=) Operator

This operator is a compound of “+” and “=” operators. It operates by adding the current value of the variable on the left to the value on the right and then assigning the result to the operand on the left.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int a = 10;
		a += 5;
		System.out.println("a: " + a);
	}

}

Output:

a: 15

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3. (-=) Operator

This operator is a compound of “-” and “=” operators. It operates by subtracting the variable’s value on the right from the current value of the variable on the left and then assigning the result to the operand on the left.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int a = 10;
		a -= 5;
		System.out.println("a: " + a);
	}

}

Output:

a: 5

4. (*=) Operator

This operator is a compound of “*” and “=” operators. It operates by multiplying the current value of the variable on the left to the value on the right and then assigning the result to the operand on the left.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int a = 10;
		a *= 5;
		System.out.println("a: " + a);
	}

}

Output:

a: 50

5. (/=) Operator

This operator is a compound of “/” and “=” operators. It operates by dividing the current value of the variable on the left by the value on the right and then assigning the quotient to the operand on the left.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int a = 10;
		a /= 5;
		System.out.println("a: " + a);
	}

}

Output:

a: 2

6. (%=) Operator

This operator is a compound of “%” and “=” operators. It operates by dividing the current value of the variable on the left by the value on the right and then assigning the remainder to the operand on the left.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int a = 10;
		a %= 5;
		System.out.println("a: " + a);
	}

}

Output:

a: 0

The post Assignment Operators in Java appeared first on OctopusCodes.

1. Logical “AND” Operator (&&)

This operator returns true when both the conditions under consideration are satisfied or are true. If even one of the two yields false, the operator results false.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int a = 10, b = 5;
		
		boolean result1 = a > 3 && b > 2;
		System.out.println("result 1: " + result1);
		
		boolean result2 = a > 30 && b > 2;
		System.out.println("result 2: " + result2);
	}

}

Output:

result 1: true
result 2: false

2. Logical “OR” Operator (||)

This operator returns true when one of the two conditions under consideration is satisfied or is true. If even one of the two yields true, the operator results true. To make the result false, both the constraints need to return false.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int a = 10, b = 5;
		
		boolean result1 = a > 3 || b > 2;
		System.out.println("result 1: " + result1);
		
		boolean result2 = a > 30 || b < 2;
		System.out.println("result 2: " + result2);
	}

}

Output:

result 1: true
result 2: false

3. Logical “NOT” Operator (!)

This operator is a unary operator and returns true when the condition under consideration is not satisfied or is a false condition.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int a = 10, b = 5;
		
		boolean result1 = !(a > 3 || b > 2);
		System.out.println("result 1: " + result1);
		
		boolean result2 = !(a > 30 || b < 2);
		System.out.println("result 2: " + result2);
	}

}

Output:

result 1: false
result 2: true

The post Logical Operators in Java appeared first on OctopusCodes.

1. “Equal to” Operator(==)

This operator is used to check whether the two given operands are equal or not. The operator returns true if the operand at the left-hand side is equal to the right-hand side, else false.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int a = 10, b = 5;
		boolean result1 = a == b;
		System.out.println("result 1: " + result1);

		int c = 7, d = 7;
		boolean result2 = c == d;
		System.out.println("result 2: " + result2);
	}

}

Output:

result 1: false
result 2: true

2. “Not Equal to” Operator(!=)

This operator is used to check whether the two given operands are equal or not. It returns true if the operand at the left-hand side is not equal to the right-hand side, else false.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int a = 10, b = 5;
		boolean result1 = a != b;
		System.out.println("result 1: " + result1);

		int c = 7, d = 7;
		boolean result2 = c != d;
		System.out.println("result 2: " + result2);
	}

}

Output:

result 1: true
result 2: false

3. “Greater than” Operator(>)

This checks whether the first operand is greater than the second operand or not. The operator returns true when the operand at the left-hand side is greater than the right-hand side.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int a = 10, b = 5;
		boolean result1 = a > b;
		System.out.println("result 1: " + result1);

		int c = 7, d = 17;
		boolean result2 = c > d;
		System.out.println("result 2: " + result2);
	}

}

Output:

result 1: true
result 2: false

4. “Greater than or equal to” Operator(>=)

This checks whether the first operand is greater than or equal to the second operand or not. The operator returns true when the operand at the left-hand side is greater than or equal to the right-hand side.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int a = 10, b = 5;
		boolean result1 = a >= b;
		System.out.println("result 1: " + result1);

		int c = 7, d = 7;
		boolean result2 = c >= d;
		System.out.println("result 2: " + result2);
		
		int e = 7, f = 14;
		boolean result3 = e >= f;
		System.out.println("result 3: " + result3);
	}

}

Output:

result 1: true
result 2: true
result 3: false

5. “Less than” Operator(<)

This checks whether the first operand is less than the second operand or not. The operator returns true when the operand at the left-hand side is less than the right-hand side.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int a = 10, b = 5;
		boolean result1 = a < b;
		System.out.println("result 1: " + result1);

		int c = 7, d = 17;
		boolean result2 = c < d;
		System.out.println("result 2: " + result2);
	}

}

Output:

result 1: false
result 2: true

6. "Less than or equal to" Operator(<=)

This checks whether the first operand is greater than or equal to the second operand or not. The operator returns true when the operand at the left-hand side is greater than or equal to the right-hand side.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int a = 10, b = 5;
		boolean result1 = a <= b;
		System.out.println("result 1: " + result1);

		int c = 7, d = 7;
		boolean result2 = c <= d;
		System.out.println("result 2: " + result2);

		int e = 2, f = 7;
		boolean result3 = e <= f;
		System.out.println("result 3: " + result3);
	}

}

Output:

result 1: false
result 2: true
result 3: true

The post Relational Operators in Java appeared first on OctopusCodes.

1. Plus Operator(+)

It is used to represent positive values. Usually, we do not write the operator before the operand. Hence, it is optional.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int number1 = 4;
		System.out.println("Number 1: " + number1);

		int result1 = +number1;
		System.out.println("After unary plus operation result 1 is " + result1);

		int number2 = -9;
		System.out.println("Number 2: " + number2);

		int result2 = +number2;
		System.out.println("After unary plus operation result 2 is " + result2);
	}

}

Output:

Number 1: 4
After unary plus operation result 1 is 4
Number 2: -9
After unary plus operation result 2 is -9

2. Minus Operator(-)

It is used to convert a positive value into a negative one.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int number1 = 4;
		System.out.println("Number 1: " + number1);

		int result1 = -number1;
		System.out.println("After unary minus operation result 1 is " + result1);

		int number2 = -9;
		System.out.println("Number 2: " + number2);

		int result2 = -number2;
		System.out.println("After unary minus operation result 2 is " + result2);
	}

}

Output:

Number 1: 4
After unary minus operation result 1 is -4
Number 2: -9
After unary minus operation result 2 is 9

3. Increment Operator(++)

It is used to increment the value of an operand by one. The operator can be applied before or after an operand.

• Pre-increment Operator: If an increment operator is written before (prefix) the operand is known as pre-increment.
• Post-increment Operator: If an increment operator is written after (postfix) the operand is known as post-increment.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int number = 4;
		System.out.println("Number: " + number);

		++number;
		System.out.println("After Pre-increment operation number is " + number);

		number++;
		System.out.println("After Post-increment operation number is " + number);
	}

}

Output:

Number: 4
After Pre-increment operation number is 5
After Post-increment operation number is 6

4. Decrement operator(– –)

It is used to decrement the value of an operand by 1. The operator can be applied before or after an operand.

• Pre-decrement Operator: If a decrement operator is written before (prefix) the operand is known as pre-decrement.
• Post-decrement Operator: If a decrement operator is written after (postfix) the operand is known as post-decrement.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		int number = 4;
		System.out.println("Number: " + number);

		--number;
		System.out.println("After Pre-decrement operation number is " + number);

		number--;
		System.out.println("After Post-decrement operation number is " + number);
	}

}

Output:

Number: 4
After Pre-decrement operation number is 3
After Post-decrement operation number is 2

5. Logical Complement Operator(!)

A logical Complement Operator is used to reverse the value of a Boolean value. It means that if the value of an operand is true, then the complement of the operator will be false and vice-versa.

Example:

package octopuscodes.com.demo;

public class Demo {

	public static void main(String[] args) {
		boolean status1 = true;
		System.out.println("Status1: " + status1);

		status1 = !status1;
		System.out.println("After logical complement operation status 1 is " + status1);

		boolean status2 = false;
		System.out.println("Status2: " + status2);

		status2 = !status2;
		System.out.println("After logical complement operation status 2 is " + status2);
	}

}

Output:

Status1: true
After logical complement operation status 1 is false
Status2: false
After logical complement operation status 2 is true

The post Unary Operators in Java appeared first on OctopusCodes.