CSE240 Lecture 10

Transcript

1. jgs CSE 240 Introduction to Programming Languages Lecture 10: Arrays

   and Pointers Javier Gonzalez-Sanchez javiergs@asu.edu PERALTA 230U Office Hours: By appointment

2. Javier Gonzalez-Sanchez | CSE240 | Spring 2018 | 2 jgs

   Arrays are Pointers #include <stdio.h> void main() { int i = 0; char a[ ] = "Hello CSE 240"; printf("\n message: %s\n ", a); while (a[i] != '\0') { a[i] = *(a + i)+1; i++;} printf("\n message after encryption: %s\n ", a); char *q; q = a; while (*q != '\0') { *q = *q-1; q++;} printf("\n message after decryption: %s\n ", a); }

3. Javier Gonzalez-Sanchez | CSE240 | Spring 2018 | 3 jgs

   Arrays are Pointers #include <stdio.h> void main() { int i = 0; char a[ ] = "Hello CSE 240"; printf("\n message: %s\n ", a); while (a[i] != '\0') { a[i] = *(a + i)+1; i++;} printf("\n message after encryption: %s\n ", a); char *q; q = a; while (*q != '\0') { *q = *q-1; q++;} printf("\n message after decryption: %s\n ", a); } a[i] = *(a + i)+ 1 a[i] = a[i]+ 1 *(a+i) = a[i]+ 1 *(a+i) = *(a+i)+ 1

4. Javier Gonzalez-Sanchez | CSE240 | Spring 2018 | 4 jgs

   Arrays are Pointers #include <stdio.h> void main() { int i = 0; char a[ ] = "Hello CSE 240"; printf("\n message: %s\n ", a); while (a[i] != '\0') { a[i] = *(a + i)+1; i++;} printf("\n message after encryption: %s\n ", a); char *q; q = a; while (*q != '\0') { *q = *q-1; q++;} printf("\n message after decryption: %s\n ", a); }

5. Javier Gonzalez-Sanchez | CSE240 | Spring 2018 | 5 jgs

   Arrays are Pointers #include <stdio.h> void main() { int i = 0; char a[ ] = "Hello CSE 240"; printf("\n message: %s\n ", a); while (a[i] != '\0') { a[i] = *(a + i)+1; i++;} printf("\n message after encryption: %s\n ", a); char *q; q = a; while (*q != '\0') { *q = *q-1; q++;} printf("\n message after decryption: %s\n ", a); } 0x48 a 0x44 H 0x48 e l l ... 0x48 q 0x94

6. Javier Gonzalez-Sanchez | CSE240 | Spring 2018 | 6 jgs

   Arrays are Pointers #include <stdio.h> void main() { int i = 0; char a[ ] = "Hello CSE 240"; printf("\n message: %s\n ", a); while (a[i] != '\0') { a[i] = *(a + i)+1; i++;} printf("\n message after encryption: %s\n ", a); char *q; q = a; while (*q != '\0') { *q = *q-1; q++;} printf("\n message after decryption: %s\n ", a); }

7. Javier Gonzalez-Sanchez | CSE240 | Spring 2018 | 7 jgs

   string.h library

8. jgs Test yourselves

9. Javier Gonzalez-Sanchez | CSE240 | Spring 2018 | 9 jgs

   1

10. Javier Gonzalez-Sanchez | CSE240 | Spring 2018 | 10 jgs

    2

11. Javier Gonzalez-Sanchez | CSE240 | Spring 2018 | 11 jgs

    3

12. Javier Gonzalez-Sanchez | CSE240 | Spring 2018 | 12 jgs

    4

13. Javier Gonzalez-Sanchez | CSE240 | Spring 2018 | 13 jgs

    5

14. jgs What about 2D arrays?

15. Javier Gonzalez-Sanchez | CSE240 | Spring 2018 | 15 jgs

    Dynamic 2D Array

16. jgs CSE 240 Introduction to Programming Languages Javier Gonzalez-Sanchez javiergs@asu.edu

    Spring 2018 Disclaimer. These slides can only be used as study material for the class CSE240 at ASU. They cannot be distributed or used for another purpose.