57 lines
1.3 KiB
C
57 lines
1.3 KiB
C
#include <stdio.h>
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int main(int argc, char *argv[])
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{
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// create two arrays we care about
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int ages[] = { 23, 43, 12, 89, 2 };
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char *names[] = {
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"Alan", "Frank",
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"Mary", "John", "Lisa"
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};
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// safely get the size of ages
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int count = sizeof(ages) / sizeof(int);
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int i = 0;
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char **first_name = &names[0];
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char **last_name = &names[count - 1];
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printf("first_name=%p last_name=%p\n", first_name, last_name);
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printf("*first_name=%s *last_name=%s\n", *first_name, *last_name);
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printf("---\n");
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// first way using indexing
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for (i = count - 1; i > -1; i--) {
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printf("%s has %d years alive.\n", names[i], ages[i]);
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}
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printf("---\n");
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// setup the pointers to the start of the arrays
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int *cur_age = ages;
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char **cur_name = names;
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// second way using pointers
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for (i = count - 1; i > -1; i--) {
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printf("%s is %d years old.\n", *(cur_name + i), *(cur_age + i));
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}
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printf("---\n");
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// third way, pointers are just arrays
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for (i = count - 1; i > -1; i--) {
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printf("%s is %d years old again.\n", cur_name[i], cur_age[i]);
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}
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printf("---\n");
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// fourth way with pointers in a stupid complex way
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for (cur_name = names, cur_age = ages;
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(cur_age - ages) < count; cur_name++, cur_age++) {
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printf("%s lived %d years so far.\n", *cur_name, *cur_age);
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}
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return 0;
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}
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