1. Blue Ridge Public School
Std: IX
Subject: Computer Applications
Operators in JAVA
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2. Operators and Operands
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Operator is a symbol or token used to perform
arithmetical or logical operations.
Operands are objects or elements that are acted upon by
operators.
Based on the number of operands, Operators are
classified as follows:
Unary Operator
Binary Operator
Ternary Operator
3. Unary Operator
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Unary operators require only one operand.
They are used to perform various operations like:
Negating or reversing the sign of an operand
Incrementing/decrementing a value by one
Inverting the value of a boolean
Unary (+) and (-) Operator:
Consider the following code snippet
public class OperatorEg1{
public static void main(String [] args)
{
int a = 8, b = -10;
System.out.println(+a);
System.out.println(-a);
System.out.println(+b);
System.out.println(-b);
}
}
The output of the above code would be:
8
-8
-10
10
4. Unary Incrementand DecrementOperators
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Unary increment operator (++) increases the value of an
operand by one.
x = x + 1 can be written as ++x or x++
Unary decrement operator (--) decreases the value of
an operand by one.
x = x – 1 can be written as ––x or x--
Increment or Decrement unary operators are of two
types:
Prefix
Postfix
5. Prefix Unary Operator
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These are applied before the operand.
The prefix form increments/decrements the value first, and
then performs the specified operation.
Consider the following code snippet:
public class prefixExample {
public static void main(String [] args) {
int a = 5;
int b = ++a;
System.out.println(a);
System.out.println(b);
}
}
The output of the above code would be:
6
6
6. Postfix Unary Operator
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These are applied after the operand.
The postfix form performs the specified operation and then
increments/decrements the value.
Consider the following code snippet:
public class postfixExample {
public static void main (String [] args) {
int a = 3;
int b = a--;
System.out.println(a);
System.out.println(b);
}
}
The output of the above code would be:
2
3
7. Prefix and Postfix Operator Example
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Consider the following code snippet:
public class OperatorExample {
public static void main(String [] args) {
int x = 10;
System.out.println(x++);
System.out.println(++x);
System.out.println(x--);
System.out.println(--x);
}
}
The output of the above code would be:
10
12
12
10
8. Logical Complement Unary Operator
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The logical operator !(NOT) is used when the result of a boolean
expression has to be reversed.
For e.g. !(8 > 3) will give the result as false because (8 > 3) is
true
Consider the following code snippet:
public class OperatorExample2 {
public static void main (String [] args) {
boolean flag = true;
boolean check = false;
System.out.println(!flag);
System.out.println(!check);
}
}
The output of the above code would be:
false
true
10. Binary Arithmetic Operators
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An arithmetic operator that operates with two operands is
known as a binary arithmetic operator.
They are used to perform addition, subtraction, multiplication,
division and find remainder/modulus.
11. Arithmetic expressions
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An expression is a combination of one or more operands and
their operators.
Arithmetic expressions compute numeric results and make use
of the arithmetic operators.
Arithmetic
Expression
Java Expression Comments
x + y
2
(x + y)/2 The parentheses are
required; else it will be
computed as x + y/2
xy
2
x*y/2 Parentheses are not
required as the operators
being of the same
precedence are evaluated
from left to right
a2+b2-c2 a*a + b*b – c*c
1ab + 1cd
3 2
1.0f/3.0f*a*b+1.0f/2.0f*c
*d
1 and 1 will be treated as
3 2
integer division and will
result in a value of 0. Hence
enforce float division by
adding decimal point with a
trailing f/F
12. Shorthand expressions
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Java allows the use of shorthand binary operations.
For e.g.
a = a + b can be written as a +=b
m = m * 10 can be written as m *= 10
c = c – d can be written as c -= d
d = d/2 can be written as d /= 2
x = x % 2 can be written as x %= 2
Shorthand expressions can be written only when the same variable is
to be used both after and before the assignment sign.
If a = 12, b = 8 find the value of a* = ++a/6 + b++ % 3;
a = a* (++a/6 + b++ % 3)
12 * (13/6 + 8%3)
12* (2 + 2)
48
Thus a = 48
13. Evaluate (Notebook work)
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If a = 4, b = 3 find the value of c = a++ * 6 + ++b * 5 + b;
If x = 4, find the value of x+ = x++ * ++x % 2;
If m = 12, find the value of n = m++ * 5 + --m;
If y = 14, find the value of z = ++y * (y++ + 5);
If m = 5 and n = 2, find the value of n after the execution of the
statement n = m + m/n;
14. Ternary Operator
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A ternary operator deals with three operands.
In Java, it is a type of conditional operator.
The ternary operator (? :) is used to evaluate a boolean
expression.
The operator decides which value to assign to the variable on
evaluation of the expression.
Syntax is as follows:
variable = (condition) ? expression1 : expression2
The above statement means that if the condition returns true,
expression1 gets assigned to the variable else expression2 gets
stored into the variable.
15. Relational Operators
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These are binary operators used to check the relation between
two operands, including equality, greater than, less than etc.
They return a boolean result after the comparison and are
extensively used in conditional statements.
16. Logical Operators
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Logical operators are used to check if a given expression is true or
false.
They are used in decision making.
The logical AND (&&) operator is used as follows:
(a > b) && (a > c)
It evaluates both the conditions and returns true only when both
the conditions are true, for all other cases it returns false.
The logical OR (||) operator is used as follows:
(a==b)||(a==c)
It returns only false when both the conditions are false, in all
other cases it returns true.
Precedence of logical operators is NOT(!), AND(&&) and OR(||)
Evaluate 5 + 3 > 7 && 7 >= 4 + 3
Note: order of operator precedence is Arithmetic, Relational and then
Logical
17. Bitwise Logical Operators
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Bitwise AND (&)
It is a binary operator that returns 1 if and only if both bits are
1, else returns 0.
Bitwise Inclusive OR (|)
It is a binary operator that returns 1 if either of the bit is 1, else
returns 0.
x y x & y
0 0 0
0 1 0
1 0 0
1 1 1
x y x | y
0 0 0
0 1 1
1 0 1
1 1 1
18. Bitwise Logical Operators
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Bitwise Exclusive OR (^)
It is a binary operator that returns 0 if both the bits are same
else returns 1.
x y x ^ y
0 0 0
0 1 1
1 0 1
1 1 0
Consider the following code snippet:
public class OperatorBitwise {
public static void main (String [] args) {
int x = 9, y = 3;
System.out.println(x & y); //bitwise AND 1001 & 0011 = 0001 = 1
System.out.println(x | y); //bitwise OR 1001 | 0011 = 1011 = 11
System.out.println(x ^ y); //bitwise XOR 1001 ^ 0011 = 1010 = 10
}
}
19. Operator precedence in Java
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In an expression, operator precedence determines the grouping of
operators with operands and determines how an expression will
evaluate.
When there are two or more operators in an expression, the
operator with the highest priority will be executed first.
20. Associativity of operators
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Associativity specifies the order in which operators with the same
precedence are executed, which can be left to right or right to
left.
Category Operator Associativity
Postfix ++ -- Left to right
Prefix + - ++ -- Right to Left
Multiplicative * / % Left to right
Additive + - Left to right
Relational < <= > >= Left to right
Equality == != Left to right
Logical AND , OR && || Left to right
Logical NOT ! Right to left
Bitwise AND OR XOR & | ^ Left to right
Ternary ?: Right to left
Assignment = += -= *= /= %= Right to left
21. Assignment (Notebook work)
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Evaluate the following arithmetic expressions:
int x = 4, find the value of x = x++ * 2 + 3 * --x;
int k = 5, j = 9, find the value of k += k++ - ++j + k;
int x = 4, find the value of x += x++ + ++x + x;
int y = 10, find the value of z = ++y * (y++ + 5);
int a = 7, find the value of a+= a++ + ++a + --a + a--;
Arrange the operators in order of higher precedence to lower precedence:
i. &&
ii. %
iii. >=
iv. ++
Evaluate the value of n, if value of p = 5, q = 19
int n = (q-p) > (p-q) ? (q-p) : (p-q);
Write the Java expression for
i. a2 + b2
2(a + b)
ii. Z = x3 + y3 - xy
3
