Operators are used to manipulate and transform data. There are two main types - arithmetic operators, which perform mathematical calculations, and relational operators, which compare two values and return a boolean result. Arithmetic operators include addition, subtraction, multiplication, division, and modulus. Relational operators include equal to, greater than, less than, greater than or equal to, less than or equal to, and not equal to. Increment and decrement operators are also used to increase or decrease a variable by 1.

2. What are Operators?
• Operators are needed to transform or
manipulate data
• Mathematical computations, comparison
of two values or setting initial values of
variables are made possible by using
arithmetic or relational operators
• Operators are important in that a
miscalculation, missed value or wrong
comparison may compromise the integrity
of a whole module or a whole program

3. What are Operators?
• The two types of
operators in this section
are:
– Arithmetic operators
– Relational operators

4. What are Operators?
• An arithmetic or logical expression is
formed by a combination of variables
or literals and an operator
• Format for an arithmetic or logical
expression:
< operand1 > operator < operand2 >
where operand1 or operand2 could be
any literal or variable name

5. Arithmetic Operators
Arithmetic operators perform mathematical
calculations on two numeric operands
Operator Description
+ Addition
- Subtraction
* Multiplication
/ Division
% Remainder after Division

6. Arithmetic Operators
• Examples of arithmetic expressions:
length * width
12.345 + 67.893 + 75.9004
• Expressions with mixed operands are evaluated
using RULES OF PRECEDENCE / ORDER OF PRECEDENCE
• Rules of precedence dictate the order of
evaluation. In this order, certain parts of the
expression gets executed first before others

7. • For arithmetic operators, the rules of
precedence (or order of evaluation) are:
1. Expressions in parentheses
2. Multiplication and Division, from left to right
3. Addition and subtraction, from left to right
• The assignment operator “=“ has the
lowest precedence
Arithmetic Operators

8. • In the expression,
answer = 4 + 6 * 2
the result of the expression
would be 16.
Arithmetic Operators

9. Arithmetic Operators
• However, if it were modified to:
answer = (4 + 6) * 2
The result of the expression
would be 20. This value would
then be assigned to the variable
answer.

10. Exercise 7.1
Arithmetic Operators
1.Which of the following evaluates to 10?
r=3, o=5, s=2, e=4, g=20, f=25
a. 3 + 5 * 2 c. 25 / 2 + 3
b. 5 + 20 / 4 d. all of the above
2. What is the value of the expression
27 – 7 * 3 / 3?
TO BE DISCUSS

11. public class RoseArithmetic
{
public static void main (String []args )
{ int a=3, b=5, c=2, d=4, e=20, f=25;
int ans;
ans = a + b * c;
System.out.println("a:" + ans);
ans = b + e / d;
System.out.println("b:" + ans);
ans = f / c + a;
System.out.println("c:" + ans);
ans = 27 - 7 * 3 /3 ;
System.out.println("2:" + ans);
}
}
TO BE DISCUSS

12. Increment and Decrement Operators
Java also has unary increment and
decrement operators that increase or
decrease the value of a variable by 1
Increment operator < operand1 > ++
Decrement operator < operand1 > --
Where operand1 could be any
literal or variable name

13. Increment and
Decrement Operators
• Example:
the expression,
count = count + 1;
could be written as
count ++;
• Increment and Decrement operators could
be POSTFIX or PREFIX as shown below

14. Operator Use Description
++ op++ the value of op was evaluated before it
was incremented
++ ++op the value of op was evaluated after it
was incremented
-- op-- the value of op was evaluated before it
was incremented
-- --op the value of op was evaluated after it
was incremented
Increment and
Decrement Operators

15. Increment and
Decrement Operators
for(start;end;operand)
Sample
for(int b2=24;b2>=1;b2--)

16. Increment and
Decrement Operators
for(int b2=1;b2<=24;b2++)
Increment
Decrement
for(int b2=24;b2>=1;b2--)

17. Exercise 7.2 Increment and
Decrement Operators
public class RoseIncrement {
public static void main(String[] args)
{
String roseName ="ROSEMARIESIBBALUCAGUIRRE",increment;
for(int b2=1;b2<=24;b2++)
{
increment = roseName.substring(0,b2);
System.out.println(increment);
}
}
}
TO BE DISCUSS

18. Exercise 7.2 Increment and
Decrement Operators
public class RoseDecrement {
public static void main(String[] args)
{
String roseName ="ROSEMARIESIBBALUCAGUIRRE",decrement;
for(int b2=24;b2>=1;b2--)
{
decrement = roseName.substring(0,b2);
System.out.println(decrement);
}
}
}
TO BE DISCUSS

19. Relational Operators
• Relational or conditional operators
perform comparison of two literals or
two variables, or any combination of
both.
• The evaluation of a conditional
expression results in a boolean value
of either true or false

20. Relational Operators
• Example: the expression
age > 18
will evaluate to only one value: true or
false

21. OPERATOR NAME DESCRIPTION
== Equal to Evaluates as true if its operands are
equivalent
> Greater than Evaluates as true when the left
operand is greater than the right
operand
< Less than Evaluates as true when the left
operand is less than the right
operand
Relational Operators

22. OPERATOR NAME DESCRIPTION
>= Greater than or
equal to
Evaluates as true when the left
operand is greater than or equal
to the right operand
<= Less than or
equal to
Evaluates as true when the left
operand is less than or equal to
the right operand
!= Not equal to Evaluates as true when both
operands are not equal
Relational Operators

23. Exercise 7.3
Relational Operators
• Determine the result of the following
conditional expressions, given the following
variables and their values:
int roseR =250; int roseO =350;
int roseS =300; int roseE = 250;
1. roseR > roseO 3. roseO <= roseS
2. roseR >= roseE 4. roseS != roseE
TO BE DISCUSS

24. int roseR = 250; int roseO = 350; int roseS =300; int roseE = 250;
//1. roseR > roseO 2. roseR >= roseE 3. roseO <= roseS 4. roseS != roseE
if (roseR > roseO)
{
System.out.println ("TRUE");
}
else
{
System.out.println("FALSE");
}
TO BE DISCUSS