完成练习15

ex10/ex10_pointer_ex15.c

@@ -0,0 +1,65 @@
+#include <stdio.h>
+
+int main(int argc, char *argv[])
+{
+    if (argc != 2)
+    {
+        printf("ERROR: You need one argument.\n");
+
+        // this is how you abort a program
+        return 1;
+    }
+
+    int i = 0;
+    char *cur_argv = *(argv + 1);
+
+    
+
+    for (i = 0; *(cur_argv + i) != '\0'; ++i)
+    {
+        // char letter = argv[1][i];
+	char letter = *(cur_argv + i);
+
+        switch (letter)
+        {
+            case 'a':
+            case 'A':
+                printf("%d: 'A'\n", i);
+
+                break;
+            case 'e':
+            case 'E':
+                printf("%d: 'E'\n", i);
+
+                break;
+            case 'i':
+            case 'I':
+                printf("%d: 'I'\n", i);
+
+                break;
+            case 'o':
+            case 'O':
+                printf("%d: 'O'\n", i);
+
+                break;
+            case 'u':
+            case 'U':
+                printf("%d: 'U'\n", i);
+
+                break;
+            case 'y':
+            case 'Y':
+                if (i > 2)
+                {
+                    // it's only sometimes y
+                    printf("%d: 'Y'\n", i);
+                }
+
+                break;
+            default:
+                printf("%d: %c is not a vowel\n", i, letter);
+        }
+    }
+
+    return 0;
+}

ex14/vedio

@@ -0,0 +1 @@
+http://ewm.ptpress.com.cn:8085/preview?qrCode=qr2018001488

ex15/ex15.c

@@ -1,31 +1,58 @@
 #include <stdio.h>
 
+int my_print(char *names[], int credits[], int n)
+{
+    for (int i = 0; i < n ;++i)
+    {
+        printf("%s%s\n%s%d\n", "name: ", names[i], "credits: ", credits[i]); 
+    }
+
+    return 0;
+}
+
 int main(int argc, char *argv[])
 {
     // create two arrays we care about
-    int ages[] = {23, 43, 12, 89, 2};
+    int credits[] = {23, 43, 12, 89, 2};
     char *names[] = {"Alan", "Frank", "Mary", "John", "Lisa"};
 
-    // safely get the size of ages
-    int count = sizeof(ages) / sizeof(int);
+    // safely get the size of credits
+    int count = sizeof(credits) / sizeof(int);
     int i = 0;
 
     // first way using indexing
-    for (i = 0; i < count; ++i)
+    // for (i = count - 1; i >= 0; --i)
+    // {
+// 	printf("%s gets %d credits.\n", names[i], credits[i]);
+    // }
+    // my_print(names, credits, count);
+    i = 0;
+    while (i < count)
     {
-	printf("%s has %d years alive.\n", names[i], ages[i]);
+        printf("%s%s\n%s%d\n", "names: ", names[i], "credits: ", credits[i]); 
+
+	++i;
     }
 
     printf("---\n");
 
     // set up the pointers to the start of the arrays
-    int *cur_age = ages;
+    // int *cur_credits = credits;
+    int *cur_credits = credits; 
     char **cur_name = names;
 
     // second way using pointers
-    for (i = 0; i < count; ++i)
+    // for (i = 0; i < count; ++i)
+    // {
+    //     printf("%s gets %d credits.\n", *(cur_name + i), *(cur_credits + i));
+    // }
+    // my_print(cur_name, cur_credits, count);
+    i = 0;
+    while (i < count)
     {
-        printf("%s is %d years old.\n", *(cur_name + i), *(cur_age + i));
+        printf("%s%s\n%s%d\n", "names: ", *(cur_name + i), "credits: ", *(cur_credits + i)); 
+
+	++i;
     }
 
     printf("---\n");
@@ -33,17 +60,22 @@ int main(int argc, char *argv[])
     // 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("%s gets %d credits again.\n", cur_name[i], cur_credits[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)
+    for (cur_name = names, cur_credits = credits; (cur_credits - credits) < count; ++cur_name, ++cur_credits)
     {
-        printf("%s lived %d years so far.\n", *cur_name, *cur_age);
+        printf("%s gets %d creditss so far.\n", *cur_name, *cur_credits);
     }
-    // int *pointer = ages;
+
+    for (i = 0; i < count; ++i)
+    {
+        printf("%s%p\n%s%p\n", "cur_name address: ", cur_name + i, "cur_credits address: ", cur_credits + i); 
+    }
+    // int *pointer = credits;
 
     // printf("sizeof(pointer):%ld", sizeof(pointer));
 

ex15/ex15_array.c

@@ -0,0 +1,51 @@
+#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");
+
+    // set up 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[0], cur_age[0]);
+    }
+    // int *pointer = ages;
+
+    // printf("sizeof(pointer):%ld", sizeof(pointer));
+
+    return 0;
+}

ex15/ex15_copy.c

@@ -0,0 +1,51 @@
+#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");
+
+    // set up 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);
+    }
+    // int *pointer = ages;
+
+    // printf("sizeof(pointer):%ld", sizeof(pointer));
+
+    return 0;
+}

ex15/ex15_pointer.c

@@ -0,0 +1,51 @@
+#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");
+
+    // set up 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);
+    }
+    // int *pointer = ages;
+
+    // printf("sizeof(pointer):%ld", sizeof(pointer));
+
+    return 0;
+}