Lab 2: C Basics

1. Lab 2: C Basics ITS100: Computer and Programming Lab. Section 1Instructor: WiratChinnan TAs: Ms. SasirassameeBuavirat Mr. ThanasanTanhermhong (Tum) Ms. PattheeraPanitsuk (Fon+) Mr. PongsateTangseng Mr. ChinorotWangtragulsang Mr. KaninAssantachai (Ob)

2. variable type printf() and scanf() %c %d %d %ld %f %lf

3. printf() • printf() is for output

4. scanf() • scanf() is for input. • Do not forget & in front of variable names.

5. Float and Integer float d; inti;

6. #include <stdio.h> int main() { int n1; printf(“Enter a Number: “); scanf(“%d”,&n1); printf(“n1 = %d\n”, n1); return 0; } Print Integer with getting input from keyboard Enter a Number: 10 n1 = 10

7. #include <stdio.h> int main() { intn1,n2; printf(“Enter 1#: “); scanf(“%d”,&n1); printf(“Enter 2#: “); scanf(“%d”,&n2); printf(“output = %d %d\n”, n1,n2); return 0; } Print Integer with getting input from keyboard Enter 1#: 10 Enter 2#: 20 output = 10 20

8. Reads in two integer and prints out the result of the first number divided by the second number. #include <stdio.h> int main() { int n1,n2, ans; printf(“Enter two numbers: ”); scanf(“%d %d”,&n1,&n2); ans = n1/n2; // mathematic expression printf(“Remainder = %d\n”, ans); return 0; } Enter two Numbers: 21 6 Remainder = 3

9. Reads in two decimal and prints out the result of the first number divided by the second number. #include <stdio.h> int main() { float n1,n2, ans; printf(“Enter two numbers: ”); scanf(“%f %f”,&n1,&n2); ans = n1/n2; printf(“Remainder = %f\n”, ans); return 0; } Enter two Numbers: 21 6 Remainder = 3.500000

10. Reads in two integer and prints out the remainder of the first number divided by the second number. #include <stdio.h> int main() { int n1,n2, ans; printf(“Enter two numbers: ”); scanf(“%d %d”,&n1,&n2); ans = n1%n2; // % means modulo operation printf(“Remainder = %d\n”, ans); return 0; } Enter two Numbers: 22 6 Remainder = 4

11. Mathematical Functions • #include<math.h> • All of these functions require arguments in float and return float

12. #include <stdio.h> #include <math.h> int main() { float n1, ans; printf(“Enter a number: ”); scanf(“%f”,&n1); ans = sqrt(n1); printf(“square root = %f\n”, ans); return 0; } Finds the square root of an input. Enter a number : 3 square root = 1.732051

13. #include <stdio.h> #include <math.h> int main() { int n1,n2, ans; printf(“Enter two numbers: ”); scanf(“%d %d”,&n1,&n2); ans = pow(n1,n2); printf(“n1 power n2 = %d\n”, ans); return 0; } Finds the power of an input. Enter two Numbers: 2 3 n1 power n2 = 8

14. To Do in Class • Exercise 1 - 5 • Call your TA when you finished. • You may take a break • Be ready for the speed test at 15.00

15. Speed Test • Speed test should be treated just like a real exam. • Rules: • No talking. Be quiet. • No mobile phone. • No electronic devices other than your PC • No Internet • No cheating • Cheating will result in a severe penalty • TAs will not help you (except when your PC crashes). • Time allowed: 45 minutes.

16. Speed Test Instruction • Write your name on the question sheet. • Create all workspace on your ‘Desktop’ and set workspace’s name follow: Sx_ID_Gx Example : S1_5322793303_G1 (for Section 1 ID 5322793303 Group 1) Example : S1_5322793303_G2 (for Section 1 ID 5322793303 Group 2) • When you finished • Raise your hand to signal the assigned TA • TA grades your work • Quietly leave the room • DO NOT bring the question sheet out. Leave it on your table.