Lecture - Operators in C++ (Book: Tony Gaddis).pptx

Operators in C++

1. Lecture-4: Operators Computer Programming 10/9/24 1

2. Lecture Contents Arithmetic & Sizeof Operators Logical & Relational Operators Assignment Operator Compound Assignment Logical Operators. 10/9/24 2

3. Arithmetic operators Arithmetic calculations * Multiplication / Division Integer division truncates remainder 7 / 5 evaluates to 1 % Modulus operator returns remainder 7 % 5 evaluates to 2 + and – Addition and Subtraction 10/9/24 3

4. Class Activity Write a program that has all the mathematical operators. +, -, /, % 10/9/24 4

5. Arithmetic operators Rules of operator precedence 10/9/24 5

6. Arithmetic operators Priority of operators a = 5 + 7 % 2; we may doubt if it really means: a = 5 + (7 % 2) with result 6 or a = (5 + 7) % 2 with result 0 Parentheses are included when one is not sure 10/9/24 6

7. Arithmetic operators Given integer variables a, b, c, d, where a = 1, b = 2, c = 3, d = 4, Evaluate the following expressions: 10/9/24 7 a + b - c + d a * b / c 1 + a * b % c a + d % b - c

8. Compound/ Combined Assignment Arithmetic Assignment Operators a = a + b; a += b; 10/9/24 8

9. Arithmetic operators Increment Operators (Unary Operator) count = count + 1; count +=1; count++; OR ++count; 10/9/24 9 int a = 5; int b = 10; int c = a * b++; int a = 5; int b = 10; int c = a * ++b; 50 55

10. Arithmetic operators Decrement Operators (Unary Operator) count = count - 1; count -=1; count--; OR --count; 10/9/24 10 postfix prefix

11. Arithmetic operators 10/9/24 11 int main() { int count = 10; cout << count << endl ; cout << ++count << endl ; cout << count << endl ; cout << count++ << endl ; cout << count << endl ; } 10 11 11 11 12

12. Sizeof () operator 10/9/24 12 Data Type No. of Bytes No. of Bits char 1 8 short 2 16 int 4 32 long 4 32 float 4 32 double 8 64 long double 10 80 sizeof ( ) returns the size in bytes a = sizeof (char); cout << a; Or cout << sizeof ( int ); It Will return the integer size in bytes on the screen

13. Sizeof () operator 10/9/24 13

14. Releational operators To evaluate comparison between two expressions Result : True / False 10/9/24 14 Assume variable x holds 10 and variable y holds 20, then:

15. Relational operators Examples (7 == 5) would return (3 != 2) would return (6 >= 6) would return If a=2, b=3 and c=6 (a*b >= c) would return true since it is (2*3 >= 6) (b+4 > a*c) would return false since it is (3+4 > 2*6) ((b=2) == a) would return true 10/9/24 15 false true true

16. Logical operators Logical expressions - expressions that use conditional statements and logical operators. && (And) A && B is true if and only if both A and B are true || (Or) A || B is true if either A or B are true ! (Not) !(condition) is true if condition is false, and false if condition is true This is called the logical complement or negation Examples (salary < 10000) || (dependants > 5) (temperature > 40.0) && (humidity > 90) !(temperature > 90.0) 10/9/24 16

17. Logical operators - Exercises NOT, AND, OR : ( !, &&, || ) Operator ! is equivalent to Boolean operation NOT ! (5 == 5) returns ! (6 <= 4) returns ! true returns ! false returns ((5 == 5) && (3 > 6)) returns false (true && false) ((5 == 5) || (3 > 6)) returns true ( true || false ). 10/9/24 17 false true false true

18. Remember && operator yields a true result only when both its operands are true. || operator yields a false result only when both its operands are false. 10/9/24 18

19. Expressions A sequence of operators and operands that specifies a computation Operand On which computation is performed E.g : c = a + b; //a & b are operands & + is an operator C = 7 + 8; // C=15 10/9/24 19

20. Escape Sequence 10/9/24 20

21. Escape Sequence Example 10/9/24 21

22. The setprecision Manipulator 10/9/24 22