Handout 12a

More Strings

1    #include <iostream.h>
2    #include <string.h>
3
4    // some character string examples
5
6    int main() {
7
8      // a character string
9      char word_a[] = "this is a word";
10
11     // an array of character strings
12     char word_b[3][10] = {"123","1234","12345"};
13
14     // a simple character pointer
15     char * ptr_a = NULL;
16
17     // an array of character pointers (initialized to NULL)
18     char * ptr_b[3] = {NULL, NULL, NULL};
19
20     // an array of character pointers that also allocates storage
21     // for character strings
22     char * ptr_c[3] = {"first", "second", "third"};
23
24     // an array of character pointers that also allocates storage
25     // for one of the pointers, all other pointers are uninitialized
26     // and no storage is associated with them
27     char * ptr_d[3] = {"storage is allocated for ptr_d[0] only"};
28
29     cout << strlen(word_a) << endl;     // treats array name as a pointer
30                                         // outputs  14
31
32     cout << strlen(word_b[0]) << endl;  // treats word_b[0] as a pointer
33                                         // outputs  3
34
35     ptr_b[0] = ptr_c[0];  // have both these pointers point at the same place
36
37     cout << ptr_b[0] << endl;  // outputs "first";
38
39     cout << strlen(ptr_d[0]) << endl;  // treats ptr_d[0] as a pointer
40                                        // outputs  38
41
42     cout << word_b << endl;        // outputs the starting address of word_b
43
44     cout << word_b[0] << endl;     // outputs the string "123"
45
46     cout << word_b[0][0] << endl;  // outputs the character '1'
47
48   }

Program Output

14
3
first
38
0x0012FF50
123
1