Operators in JAVA
Operator are the symbols that are used to manipulate the data items. Different types of operators are available in java. Some of them are discussed below.
- Arithmetic Operators
- Increment or decrement operators
- Relational Operators
- Logical Operators
- Assignment Operators
- Conditional Operator
Precedence of operators
Precedence of operators means when several operations occur in an expression, which one will be evaluated first? Next what? It means the priority. So, each part is evaluated and resolved in a previously designed order called operator precedence. Usually we use the BODMAS rule in normal calculation. But here it is something like that. This affects how an expression is evaluated. Certain operators have higher precedence than others; for example, the multiplication operator has higher precedence than the addition operator.
Example
Now, let us evaluate the statements below
class student
{
public static void main(String[] args)
{
int x=15-3*2;
System.out.println(x);
}
}
now can you find what is the value of x?
will it be 24 ? (After deduction of 3 from 15 we got 12 and then this is multiplied by 2)
will it be 9 ? (After multiplication of 3 and 2 we got 6 and deduct same from 15)
here 3 is sharing both “*” and “-“. So when two operators share a common operand, the operator with the highest precedence is operated first. In java “*” has higher precedence than “–“ that is why it will be operated first. And thus result will be 9.
Another example
Class student
{
public static void main(String[] args)
{
int a = 10, b = 5, c = 1, result;
result = a-++c-++b;
System.out.println(result);
}
}
If it is executed the output will be 2
Let us see how?
The operator precedence of prefix “++” is higher than “-“ operator.
So the expression a-++c-++b; is equivalent to result = a-(++c)-(++b);
So, when dealing with multiple operators and operands in an single expression, you can use parentheses for clarity.
Arithmetic Operators
Arithmetic operators are called binary operator. They require one operator and two operands (on which operator works)
Details about arithmetic operators are given below with different programming examples
+ – addition
– – subtraction
* – multiplication
/ – division
% – modulo (this is used to keep the reminder)
Programming examples of arithmetic operators
þ Addition example
Write a java program to add two numbers
public class student
{
public static void main(String []args)
{
int x=12;
int y= 20;
int z;
z= x+y;
System.out.println(x);
System.out.println(y);
System.out.println(“Result is “+z);
}
}
Output
12
20
Result is 32
þ Subtraction example
Write a java program to subtract two numbers
public class student
{
public static void main(String []args)
{
int x=34;
int y= 19;
int z;
z= x-y;
System.out.println(x);
System.out.println(y);
System.out.println(“Result is “+z);
}
}
Output
34
19
Result is 15
þ Multiplication example
Write a java program to multiply two numbers
public class student
{
public static void main(String []args)
{
int x=34;
int y= 5;
int z;
z= x*y;
System.out.println(x);
System.out.println(y);
System.out.println(“Result is “+z);
}
}
Output
34
5
Result is 170
þ Division example
Write a java program to divide two numbers
public class student
{
public static void main(String []args)
{
int x=12;
int y= 20;
int z;
z= y/x;
System.out.println(y);
System.out.println(x);
System.out.println(“Result is “+z);
}
}
Output
20
12
Result is 1
þ Modulo example
Write a java program to divide two numbers and keep the reminder
public class student
{
public static void main(String []args)
{
int x=12;
int y= 20;
int z;
z= y%x;
System.out.println(y);
System.out.println(x);
System.out.println(“Result is “+z);
}
}
Output
20
12
Result is 8
Increment or decrement operators
Increment or decrement operators are called unary operators. They require one operator and one operator. ++ Means to increase the value of the variable by 1 and – – means to decrease the value of the variable by 1
Details about increment or decrement operators are given below with different programming examples
++ – increment
— – decrement
Programming examples of increment and decrement operators
þ Increment example
public class student
{
public static void main(String []args)
{
int x=12;
x++;
System.out.println(“Result is “+x);
}
}
Output
Result is 13
Another increment example (Post increment)
public class student
{
public static void main(String []args)
{
int x=12;
int y;
y=x++;
System.out.println(“Result is “+x);
System.out.println(“Result is “+y);
}
}
Output
Result is 13
Result is 12
Another increment example (Pre increment)
public class student
{
public static void main(String []args)
{
int x=12;
int y;
y=++x;
System.out.println(“Result is “+x);
System.out.println(“Result is “+y);
}
}
Output
Result is 13
Result is 13
þ Decrement example
public class student
{
public static void main(String []args)
{
int x=12;
x–;
System.out.println(“Result is “+x);
}
}
Output
Result is 11
Another Decrement example (Post decrement)
public class student
{
public static void main(String []args)
{
int x=12;
int y;
y=x–;
System.out.println(“Result is “+x);
System.out.println(“Result is “+y);
}
}
Output
Result is 11
Result is 12
Another Decrement example (Pre decrement)
public class student
{
public static void main(String []args)
{
int x=12;
int y;
y=–x;
System.out.println(“Result is “+x);
System.out.println(“Result is “+y);
}
}
Output
Result is 11
Result is 11
NB – When increment and decrement operators are assigning its value to other variable or printing its value written as above program segments :- in case of post increment first it assigns its value then increment itself by 1. And in case of pre increment first in increases its value by 1 and then it assigns value. Same thing is applicable for decrement operators.
In the above example y=x++; is called post increment. First value of x will be assigned to y and then the value of x will be increased by 1. y=+++; is called pre increment. First value of x is will be increased by 1 and then the result will be assigned to y. same thing is applicable for decrement operators.
Relational Operators
Relational operators are also called binary operators. They require one operator and two operands. They return Boolean value either true or false.
Details about relational operators are given below with different programming examples
< – less than
> – greater than
<= – less than or equal to
>= – greater than or equal to
== – equal to (checks for equality)
!= – not equal to
Programming examples of relational operators
þ Less than example
public class student
{
public static void main(String []args)
{
int x=12;
int y=30;
boolean z;
z=x<y;
System.out.println(“Result is “+z);
}
}
Output
Result is true
þ Greater than example
public class student
{
public static void main(String []args)
{
int x=12;
int y=30;
boolean z;
z=x>y;
System.out.println(“Result is “+z);
}
}
Output
Result is false
þ Equal to example
public class student
{
public static void main(String []args)
{
int x=30;
int y=30;
boolean z;
z=x==y;
System.out.println(“Result is “+z);
}
}
Output
Result is true
þ Not equal to example
public class student
{
public static void main(String []args)
{
int x=12;
int y=30;
boolean z;
z=x!=y;
System.out.println(“Result is “+z);
}
}
Output
Result is true
public class student
{
public static void main(String []args)
{
int x=12;
int y=12;
boolean z;
z=x!=y;
System.out.println(“Result is “+z);
}
}
Output
Result is false
Logical Operators
Logical operators are also called binary operators. They require one operator and two operands. They return Boolean value either true of false
Details about logical operators are given below with different programming examples
&& – logical and
|| – logical or
! -logical not
Programming examples of logical operators
þ Logical “and” example
public class student
{
public static void main(String []args)
{
boolean x=true;
boolean y=false;
boolean z;
z=x &&y;
System.out.println(“Result is “+z);
}
}
Output
Result is false
þ Logical or example
public class student
{
public static void main(String []args)
{
boolean x=true;
boolean y=false;
boolean z;
z=x || y;
System.out.println(“Result is “+z);
}
}
Output
Result is true
þ Logical not example
public class student
{
public static void main(String []args)
{
boolean x=true;
boolean y=false;
boolean z;
z=x&&!y;
System.out.println(“Result is “+z);
}
}
Output
Result is true
Assignment Operators
These operators are also called binary operator. They require one operator and two operands. It assigns the right hand value to left hand value.
Details about assignment operators are given below with different programming examples
Simple assignment
= – equal to
Programming examples of assignment operators
þ Equal to
public class student
{
public static void main(String []args)
{
int x=12,y;
y=x;
System.out.println(“Result is “+x);
System.out.println(“Result is “+y);
}
}
Output
Result is 12
Result is 12
Compound assignment
+= -add and assign
-= -subtract and assign
*= -multiply and assign
/= -divide and assign
%= -modulo and assign
Programming examples of compound assignment operators
þ Add and assign example
public class student
{
public static void main(String []args)
{
int x=12;
x+=10; //x=x+10
System.out.println(“Result is “+x);
}
}
Output
Result is 22
þ Subtract and assign example
public class student
{
public static void main(String []args)
{
int x=34;
x-=5; //x=x-5
System.out.println(“Result is “+x);
}
}
Output
Result is 29
þ Multiply and assign example
public class student
{
public static void main(String []args)
{
int x=12;
x*=10;
System.out.println(“Result is “+x);
}
}
Output
Result is 120
þ Divide and assign example
public class student
{
public static void main(String []args)
{
int x=12;
x/=10;
System.out.println(“Result is “+x);
}
}
Output
Result is 1
þ Modulo and assign example
public class student
{
public static void main(String []args)
{
int x=12;
x%=10;
System.out.println(“Result is “+x);
}
}
Output
Result is 2
Conditional Operator
This operator is known as ternary operators as it requires three operands. This also works on Boolean value.
Details about conditional operator is given below with different programming examples
(? 🙂 – conditional operator
Programming examples of conditional operator
public class student
{
public static void main(String []args)
{
int x=10;
int y=2;
int z;
z=(x>y)? x : y;
System.out.println(“Result is “+z);
}
}
Output
Result is 10
Another Example of conditional operator
public class student
{
public static void main(String []args)
{
int x=10;
int y=20;
String z;
z=(x>y)? x+”is greater” : y+”is greater”;
System.out.println(“Result is “+z);
}
}
Output
Result is 20is greater
Type Casting
Before explaining about type casting let us try a program in corejava that is given below. Type this program and see the output.
import java.util.Scanner;
class student
{
public static void main(String args[])
{
int a=20,b=9,c;
c=a/b;
System.out.println(c);
}
}
Definitely the output will be 2. Because integer variable keeps only integer data.
Again let us modify the above program and declare c as float and see the output.
Definitely the output will be 2.0. Because float variable keeps only float data but getting integer from the expression.
Again let us modify the above program and we will do the type casting and we will write following code
c=(float)a/b;
in this case definitely the output will be 2.2222223
From the above explanation we got that assigning a value of one type to a variable of another type is known as Type Casting.