ex15

lcthw-remnants-2/.gitignore

@@ -12,3 +12,4 @@ ex11
 ex12
 ex13
 ex14
+ex15

lcthw-remnants-2/ex15.c

@@ -0,0 +1,54 @@
+#include <stdio.h>
+
+int main(int argc, char *argv[])
+{
+  // create two arrays we care about
+  int ages[] = {23, 43, 12, 89, 2};
+  char *names[] = {
+    "Alan", "Frank",
+    "Mary", "John", "Lisa"
+  };
+
+  // safely get the size of ages
+  int count = sizeof(ages) / sizeof(int);
+  int i = 0;
+
+  // first way using indexing
+  for(i = 0; i < count; i++) {
+    printf("%s has %d years alive.\n",
+        names[i], ages[i]);
+  }
+
+  printf("---\n");
+
+  // setup the pointers to the start of the arrays
+  int *cur_age = ages;
+  char **cur_name = names;
+
+  // second way using pointers
+  for(i = 0; i < count; i++) {
+    printf("%s is %d years old.\n",
+        *(cur_name+i), *(cur_age+i));
+  }
+
+  printf("---\n");
+
+  // third way, pointers are just arrays
+  for(i = 0; i < count; i++) {
+    printf("%s is %d years old again.\n",
+        cur_name[i], cur_age[i]);
+  }
+
+  printf("---\n");
+
+  // fourth way with pointers in a stupid complex way
+  for(cur_name = names, cur_age = ages;
+      (cur_age - ages) < count;
+      cur_name++, cur_age++)
+  {
+    printf("%s lived %d years so far.\n",
+        *cur_name, *cur_age);
+  }
+
+  return 0;
+}