Operator is a symbol that
performs a specified operation between the data items. Java provides the following different types
of operators.
a) Arithmetic operators:
Operator Meaning
+ Addition
-
Subtraction
* Multiplication
/ Division
% Modulus
Example:
class arope
{
public static void main(String[] args)
{
int a,b,sum,sub,mul,div,mod;
a=Integer.parseInt(args[0]);
b=Integer.parseInt(args[1]);
sum=a+b;
sub=a-b;
mul=a*b;
div=a/b;
mod=a%b;
System.out.println("Addition="+sum);
System.out.println("Subtraction="+sub);
System.out.println("Multiplication="+mul);
System.out.println("Division="+div);
System.out.println("Remainder="+mod);
}
}
b) Arithmetic Assignment
Operators:
Syntax: variable operator = expression
Which
is equivalent to
variable = variable operator expression
Operator Example Equivalent Expression
+ = a
+ = 4 a = a + 4
- = a
- = 5 a
= a – 5
* = a
* = 3 a = a * 3
/ = a / = 8 a = a / 8
% = a
% = 5 a = a % 5
c) Assignment Operator:
‘=’ is an assignment operator used to assign the value to a variable.
Syntax: variable = value;
Example: a = 7;
d)
Increment and Decrement Operators: ‘++’ and ‘--' are Java’s increment
and decrement operators. The increment
operator increased its operand by one.
The decrement operator decreased its operand by one.
Example:
class
a
{
public static void main(String[]
args)
{
int x=4;
System.out.println("x++:"+
++x); //O/P: 5
int y=10;
System.out.println("x++:"+
y++); //O/P: 5
int p=5;
int t=--p+3;
System.out.println("t
:"+t); //O/P: 7
}
}
e)
Relational Operators: Relational Operators determines the relationship
between the two operands.
Operator Meaning Example
= = equal to A= =B
!= Not
equal to A!=B
> Greater
than A>B
< Less
than A<B
>= Greater than or equal to A>=B
<= Less than or equal to A<=B
f)
Logical Operators: Logical operators are used to check for compound conditions,
which are formed, by the combination of two or more relational
expressions. Java provides the following
logical operators and these are follows truth tables and produce Boolean
values.
Operators: Logical AND &&
Logical OR
||
Logical NOT !
Truth
table for Logical AND(&&):
Op1 Op2 Op1 && Op2
T T T
T F F
F T F
F F F
Truth
table for Logical OR(||):
Op1 Op2 Op1 && Op2
T T T
T F T
F T T
F F F
Truth table for
Logical NOT(!):
Op1 !Op1
T F
F T
g) Conditional
Operator: Java has a decision operator called conditional
operator. “? :” are conditional
operators. These operators are also
called ternary operators.
Syntax: testconditon ? expression1 : expression2
Here, if the
testcondition is true, then expression1 is evaluated otherwise, expression2 is
evaluated.
Example: max = (a>b) ? a : b;
h)
Bit-wise Operators: The following bit-wise operators are provided by
Java. These operators act upon the
individual bits on their operands.
Operator Meaning
~ Bit-wise unary NOT
& Bit-wise AND
| Bit-wise OR
^ Bit-wise exclusive OR
>> Shift right
<< Shift left
|= Bit-wise OR Assignment
^= Bit-wise exclusive OR
Assignment
>>= Shift right Assignment
<<= Shift left Assignment
These operators act upon the
individual bits on their operands.
Bit-wise Logical Operators (&, |, ^ and ~) follows the following
truth tables
Op1
Op2 Op1|Op2 Op1&Op2 Op1^Op2 ~Op1
0 0 0 0 0 1
1 0 1 0 1 0
0 1 1 0 1 1
1 1 1 1 0 0
javax.swing: It is package
contains an important class called JOptionPane class. This class is used to display dialog
boxes. It provides two important
predefined methods showInputDialog and showMessageDialog called static
methods. Such methods are always used
their class name followed by a dot operator.
ShowInputDialog:
showInputDialog is a method of class
JOptionPane. It is a static method and
the general format is as
Syntax: JOptionPane.showInputDialog(argument);
The argument indicates to the user what to do in the
text field.
Example: JOptionPane.showInputDialog(“Enter a value”);
When we
perform this operation the input dialog box is available as
The
users types characters in the text field then clicks the ok button, it returns
string to the program.
showMessageDialog:
showMessageDialog is method of class JOptionPane. It is a static method. The general format of showMessageDialog is in
two ways.
Syntax1: JOptionPane.showMessageDialog(null,argument1);
The
first argument must be null keyword. The
second argument is the string that is required to display. The title bar of message dialog contains the
string “Message” to indicate that the dialog is presenting a message to the
user. The default icon is
INFORMATION_MESSAGE.
Example:
JOptionPane.showMessageDialog(null,”value=”+x);
Syntax2:
JOptionPane.showMessageDialog(null,argument2,argument3,argument4)
The first argument must be null keyword. The second argument is the message to
display. The third argument is the
string to display in the title bar of the dialog. The fourth argument is a value indicating the
type of message dialog to display.
For
argument4 some of the message dialogs are
JOptionPane.PLAN_MESSAGE
JOptionPane.ERROR_MESSAGE
JOptionPane.INFORMATION_MESSAGE
JOptionPane.WARNING_MESSAGE
JOptionPane.QUESTION_MESSAGE
Example:
JOptionPane.showMessageDialog(null,”value=”+x,”output”,
JOptionPane.ERROR_MESSAGE)
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