Java operators

Written By Sar Maroof - Sarmaroof.com

Java supports different types of operators. Here the Relational operators and the Logical operators are explained using Java Codes and exercises.

Java Operators: Article Quizzes

operators

1- Relational Operators

Relational operators are binary operators, and their operands are numeric expressions. The result of the evaluation is either true or false.

Example is: if ( i == 20 ) this asks “does i equal to 20?” if it is true, the statement is executed. The statement is ignored if i is not equal to 20, because the result is false.

The relational operators in Java are:

==	Equal
!=	Not equal
<	Less than
<=	Less than or equal to
>	Greater than
>=	Greater than or equal to

Exercise 1

What is written to the standard output as the result of executing the following statements?

class RelationalOperator {

	public static void main(String[] args){

		int i = 8;

		if(i != 7) {
			System.out.print("X");
		}
		else {
			System.out.print("Y");
		}
	}
}

Exercise 2

What is written to the standard output as the result of executing the following statements?

class RationalOperator {

	public static void main(String[] args){

		int i = 100;

		if(i <= 30) {
			System.out.print("M");
		}
		else {
			System.out.print("O");
		}
	}
}

Exercise 3

What is written to the standard output as the result of executing the following statements?

class RelationalOperator {

	public static void main(String[] args){

		int i = 10;
		int i2 = 20;
		int i3 = 30;

		if(i3 <= 30) {
			System.out.print("K");
		}
		if(i == i3) {
			System.out.print("L");
		}
		if(i3 >= 22) {
			System.out.print("M");
		}
		if(i2 > 18) {
			System.out.print("N");
		}
		if(i != 10) {
			System.out.print("O");
		}
	}
}

2- Conditional Operators

The conditional operators in Java ( &&, || ) are used in conditional statements such as if and while statements. The following example shows the difference between “&&” and “||”

int i = 4; int r = 6;

if(i == 4 && r ==3 ) // By using “&&” the result is false, because r is not equal to 3. One false results in false.

if(i ==4 || r ==3) // By using “||” the result is true, because i is equal to 4. One true results in true.

&&	AND
\|\|	OR

Exercise 4

What is written to the standard output as the result of executing the following statements?

class LogicalOperator {

	public static void main(String[] args){

		int i = 10;

		if(i > 9 && i != 10) {
			System.out.print("P");
		}
		else {
			System.out.print("Q");
		}
	}
}

Exercise 5

What is written to the standard output as the result of executing the following statements?

class LogicalOperator {

	public static void main(String[] args){

		int i = 10;

		if(i != 9 || i > 20) {
			System.out.print("W");
		}
		else {
			System.out.print("Z");
		}
	}
}

Exercise 6

What is written to the standard output as the result of executing the following statements?

class LogicalOperator {

	public static void main(String[] args){

		int i = 10;
		int i2 = 20;
		int i3 = 30;

		if(i3 == 30 && i2 > 20) {
			System.out.print("R");
		}
		if(i != i3 || i2 == 21) {
			System.out.print("S");
		}
		if(i3 >= 22 && i != 11) {
			System.out.print("T");
		}
		if(i2 > 18 || i == 11) {
			System.out.print("U");
		}
	}
}

Please, leave your questions, feedback and suggestions in the comments below!
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Java Operators: Article Quizzes