1. Intro to Programming Week # 3 If-else Statement Lecture # 6
Department of Computer Science & Engineering
Air University
Intro to Programming Week # 3 If-else Statement Lecture # 6
By: Saqib Rasheed

2. Programs executed sequentially by default
Control Structures
3 control structures
Sequence structure
Programs executed sequentially by default
Selection structures (conditional instructions)
if, if/else, switch
Repetition structures (loop/jump instructions)
while, do/while, for

3. Flow Chart for if statement
Connectors will come at the end
By: Saqib Rasheed
Air University

4. if Statement The if statement allows conditional execution
if (condition) {
statement ; - }
The if statement allows conditional execution
By: Saqib Rasheed
Air University

5. Practice Example # 1
main () { int num; cout<<“Enter a number less than 10:”; cin>>num; If (num <10) cout<<“What a obedient students” }
By: Saqib Rasheed
Air University

6. Relational Operators
The relational operators allow to compare two values
Whether they are equal to each other.
Unequal
Whether one is greater than the other.
By: Saqib Rasheed
Air University

7. Relational Operators
By: Saqib Rasheed
Air University

8. We can even use arithmetic expressions in the if statement
We can even use arithmetic expressions in the if statement. if ( % 5 ) cout<<"This works"; if ( a = 10 ) cout<<"Even this works"; if ( -5 ) cout<<"Surprisingly even this works";
By: Saqib Rasheed
Air University

9. Practice Example # 2 int var1, var2;
cout<<"Input the first number:";
cin>>var1;
cout<<"Input the second number:";
cin>>var2;
if(var1 == var2) {
cout<<"var1 is equal to var2"; }
By: Saqib Rasheed
Air University

10. Practice Example # 3
int main() { int n,d; cout << "Enter two positive integers: "; cin >> n >> d; if (n%d) cout << n << " is not divisible by " << d ; }
By: Saqib Rasheed
Air University

11. if-else Entry point for if-else block Exit point for if-else block
Connectors at the end
Exit point for if-else block
By: Saqib Rasheed
Air University

12. if-else if (condition) { statement ; - } else By: Saqib Rasheed
Air University

13. Practice Example # 4
cout<<“Enter a number less than Equal to 10:”; cin>>num; If (num <=10) { cout<<“What a obedient students” } else cout<<“You are not obedient Student”;
By: Saqib Rasheed
Air University

14. Practice Example # 5 int var1, var2;
cout<<"Input the first number:";
cin>>var1;
cout<<"Input the second number:";
cin>>var2;
if(var1 == var2) {
cout<<"var1 is equal to var2"; }
else
cout<<"var1 is not equal to var2";
By: Saqib Rasheed
Air University

15. Example Nested if int var1,var2,var3,var4; var1=12; var2=12; var3=10;
if(var1 == var2) {
cout<<"\nOuter Loop Statement";
if (var3 == var4)
cout<<"\nVar1 & Var2 are Equal and Var3 & var4 are Equal"; }
cout<<"\nMain Statement";
By: Saqib Rasheed
Air University

16. Largest Number among 3 Write a program in C++ that take input
Que No 1
Write a program in C++ that take input
of three integers numbers from user.
Find the largest number among three
of them.
By: Saqib Rasheed
Air University

17. Largest Number among 3 (Code)
#include<iostream.h> void main () { int a,b,c, larg; cout<<"Enter First Integer="; cin>>a; cout<<"Enter Second Integer="; cin>>b; cout<<"Enter Third Integer="; cin>>c;
By: Saqib Rasheed
Air University

18. Largest Number among 3 (Code)
if (a > b) larg = a; else larg = b; if (larg > c ) cout<<"Largest is ="<<larg<<endl; cout<<"Largest is ="<<c<<endl; }
By: Saqib Rasheed
Air University

19. Largest Number among 3 (Out Put)
Enter First Integer=10 Enter Second Integer=25 Enter Third Integer=38 Largest is =38 Press any key to continue
By: Saqib Rasheed
Air University

20. Nested if else
Que No 2 Write a program in C++ using if/else operator with nested statements to find the grade of a student . marks >= 90  Grade A marks >= 80  Grade B marks >=70  Grade C marks >=60  Grade D
By: Saqib Rasheed
Air University

21. Nested if else (Code)
#include<iostream.h> void main () { int marks; cout<<"Enter the grade of student="; cin>>marks; if ( marks >= 90 ) cout<< " Grade A \n"; else if (marks >= 80 ) cout<<" Grade B \n";
By: Saqib Rasheed
Air University

22. Nested if else (Code)
else if ( marks >=70 ) cout<<" Grade C \n"; else if (marks >=60) cout<<" Grade D \n"; else { cout<<" Grade F \n"; cout<<" You have to take the classes again\n"; cout<<" Work Hard To Get Good Grade\n"; }
By: Saqib Rasheed
Air University

23. Nested if - else int n1,n2,n3; cout << "Enter three integers: ";
cin >> n1 >> n2 >> n3;`
if (n1 < n2)
if (n1 < n3) `
cout << "Their minimum is " << n1 << endl;
else
cout << "Their minimum is " << n3 << endl;
else if (n2 < n3)
cout << "Their minimum is " << n2 << endl;
By: Saqib Rasheed
Air University

24. Nested if-else
main( ) { int i ; cout<< "Enter either 1 or 2 "; cin>>i ; if ( i == 1 ) cout<<"You would go to heaven !";
By: Saqib Rasheed
Air University

25. Nested if-else else { if ( i == 2 )
cout<<"Hell was created with you in mind";
cout<<"How about mother earth !"; }
By: Saqib Rasheed
Air University

26. Forms of if The if statement can take any of the following forms:
(a) if ( condition )
do this ;
(b) if ( condition ) {
and this ; }
By: Saqib Rasheed
Air University

27. Forms of if -else (c) if ( condition ) do this ; else
By: Saqib Rasheed
Air University

28. Forms of if -else (d) if ( condition ) { do this ; and this ; } else
By: Saqib Rasheed
Air University

29. Forms of if -else
(e) if ( condition ) do this ; else { if ( condition ) and this ; }
By: Saqib Rasheed
Air University

30. Forms of if -else
(f) if ( condition ) { if ( condition ) do this ; else and this ; }
By: Saqib Rasheed
Air University

31. Logical Operators AND && OR || Not ! Bitwise Operator | &
By: Saqib Rasheed
Air University

32. Logical Operators If a is greater than b AND c is greater than d
In C++
if(a > b && c> d)
if(age > 18 || height > 5)
By: Saqib Rasheed
Air University

33. The Conditional Operators
The conditional operators ? and : are sometimes called ternary operators
since they take three arguments
expression 1 ? expression 2 : expression 3
By: Saqib Rasheed
Air University

34. Example of Condition Operator
int x, y ;
cin>>x;
y = ( x > 5 ? 3 : 4 ) ;
This statement will store 3 in y if x is greater than 5, otherwise it will store 4 in y.
By: Saqib Rasheed
Air University

35. Hierarchy of Operators
By: Saqib Rasheed
Air University

36. Vowel / Consonant
Que No 3 Write a program in C++ to input a single character and print a message“ It is vowel" if it is vowel otherwise print message "It is a "consonant“ Use if-else structure and OR (||) operator only
By: Saqib Rasheed
Air University

37. Vowel / Consonant (Code)
#include<iostream.h> void main() { char input; cout<<"Input a single character-->"; cin>>input; if (input == 'a' || input == 'e'|| input == 'i' ||input == 'o'|| input == 'u‘) cout<<"Its a VOWEL\n“; else cout<<"Its a CONSONANT\n“; }
By: Saqib Rasheed
Air University

38. Odd/ Even
Que No 4 Write a Program in C++ that take an Integer value’s from the user and tell that the number Is EVEN or ODD
By: Saqib Rasheed
Air University

39. Odd/ Even (Code)
int value; cout<<"Enter an Interger value "; cin>>value; if (value % 2 == 0) cout<<"Your number is Even\n"; else cout<<"Your number is Odd\n“;
By: Saqib Rasheed
Air University

40. Small / Capital Letter
Que No 5 Write a program in C++ that take a single character from the user, and tells it's a Small Letter or it's a CAPITAL letter using nested if statement only
By: Saqib Rasheed
Air University

41. Small / Capital Letter (Code)
char letter; cout<<"Enter the letter in \"CAPITAL\" or in \"SMALL\"-->"; cin>>letter; if (letter >='A' && letter <= 'Z') { cout<<"\n\nYou Entered a Capital Letter\n"; if (letter == 'a' || letter == 'e'|| letter == 'i' || letter == 'o'|| letter == 'u' || letter == 'A' || letter == 'E'|| letter == 'I' || letter == 'O'|| letter == 'U') cout<<"\n\nIts a VOWEL\n"; else cout<<"\n\nIts a CONSONANT\n“; }
By: Saqib Rasheed
Air University

42. Small / Capital Letter (Code)
else if (letter >= 'a' && letter <= 'z') {
cout<<"\n\nYou Entered a Small Letter\n";
If (letter == 'a' || letter == 'e'|| letter == 'i' || letter == 'o'|| letter =='u' ||
letter == 'A' || letter == 'E'|| letter == 'I' || letter == 'O'|| letter == 'U')
cout<<"\n\nIts a VOWEL\n";
else
cout<<"\n\nIts a CONSONANT\n“; }
else cout<<"\n\nIts Not a letter";
cout<<endl;
return 0; }
By: Saqib Rasheed
Air University

43. Condition Operator (?:)
Que No 6 Write a Program in C++ to input a single letter in a char variable. If "m" is input print "You are Male” otherwise "You are Female" by Using Condition Operator (?:)
By: Saqib Rasheed
Air University

44. Condition Operator (?:)
#include<iostream.h> void main () { char gender; cout<<"Enter the Gender of the Person="; cin>>gender; /*(?:) First Value is Printed if the condition is true and if it is false second condition is printed*/ cout<<( gender>= 'm' ? "You are Male\n" : "You are Female\n"); }
By: Saqib Rasheed
Air University

45. Temperature Program Que No 7
Make a program in C ++ that tells the form of
Water whether it is Ice, Water or Steam. Display
the menu also as under.
Temperature Less than 0 = ICE
Temperature Greater than 0 & Less than 100 = Water
Temperature Greater than 100 = STEAM
By: Saqib Rasheed
Air University

46. Temperature Program
int t; cout<<"Temperature Less than 0 = ICE \n" <<"Temperature Greater than 0 & " <<"Temperature Less than 100 = Water\n" <<"Temperature Greater than 100 = STEAM\n"; cout<<"\n\n\t\tPlease enter the Temperature="; cin>>t;
By: Saqib Rasheed
Air University

47. Temperature Program if ( t <= 0 )
cout<<"Form of water is \"ICE\""<<endl;
else
if( t > 0 && t < 100 )
cout<<"Form is \"WATER\"\n";
if ( t >= 100 )
cout<<"Form of water is \"steam\"\n";
By: Saqib Rasheed
Air University

48. Assignment
Write a program to calculate the salary as per the following table
By: Saqib Rasheed
Air University