C programming/Structures - Revision history

Heth: /* Typedef simple */

2019-05-17T10:29:28Z

‎Typedef simple

2019-05-17T10:29:15Z

‎Typedef simple

2019-04-23T09:01:33Z

2016-10-09T08:50:30Z

‎Using a copy

2016-10-09T08:50:01Z

‎Using a copy

2016-10-09T08:48:26Z

‎Structures in function calls

2012-03-06T06:59:40Z

‎Structures in function calls

2012-03-06T06:59:12Z

‎Example 3

2010-11-21T15:12:22Z

‎Arrays of structures example

2010-11-21T14:01:04Z

‎Arrays of structures example

@@ Line 190: / Line 190: @@
 </source>
 =Typedef simple=
->source lang=c>
+<Source lang=c>
 typedef struct {
    int k;

@@ Line 190: / Line 190: @@
 </source>
 =Typedef simple=
-source lang=c>
+>source lang=c>
 typedef struct {
    int k;

@@ Line 188: / Line 188: @@
+     }
+}
 </source>
 [[Category:C]]

@@ Line 142: / Line 142: @@
      adjustTimzone( t );
-     printf("The time is %02i:%02i:%02i\n", t.hour, t.min, t.sec);  //Will print 00:00:00 in this example
+     printf("The time is %02i:%02i:%02i\n", t.hour, t.min, t.sec);  //Will WRONGLY print 00:00:00 in this example
+}
 </source>

@@ Line 126: / Line 126: @@
 adjustTimezone( struct TimeStruct t ) {
-     t.hour += TIMEZONE;   // Add TIMEZONE hours -> means via pointer
+     t.hour += TIMEZONE;   // Add TIMEZONE hours to the copy!!
-     //Code to check if t->hour < 0 or > 23
+     //The copy is deleted when this function returns
+}

@@ Line 72: / Line 72: @@
 </source>
 =Structures in function calls=
-To use structures in function calls, a pointer to the structure is used in the function call. The function therefore works on the original structure and not a copy.
+There are two options when using structures in function calls:
 <source lang=c>
 #include <stdio.h>
@@ Line 103: / Line 107: @@
      adjustTimzone( &t );
-     printf("The time is %02i:%02i:02i\n", t.hour, t.min, .t.sec);  //Will print 00:01:00 in this example
+     printf("The time is %02i:%02i:%02i\n", t.hour, t.min, t.sec);  //Will print 00:01:00 in this example
+}
 </source>

@@ Line 87: / Line 87: @@
 adjustTimezone( struct TimeStruct *t ) {
-     t->hour += TIMEZONE;   // Add TIMEZONE hours
+     t->hour += TIMEZONE;   // Add TIMEZONE hours -> means via pointer
      //Code to check if t->hour < 0 or > 23
+}

@@ Line 78: / Line 78: @@
 #define STUDENTS 16
 #define FREE 0
-#define POPULATE(FIELD,ID, NAME, SURNAME) class[FIELD].id = ID, \
+#define POPULATE(FIELD, ID, NAME, SURNAME) class[FIELD].id = ID, \
                                            strcpy(class[FIELD].name,NAME), \
                                            strcpy(class[FIELD].surname,SURNAME)
@@ Line 102: / Line 102: @@
      class[0].id = 101; strcpy(class[0].name,"Henrik"); strcpy(class[0].surname,"Thomsen");
      class[7].id = 145; strcpy(class[7].name,"Anders"); strcpy(class[7].surname,"And");
-     POPULATE(3,78,"Kaptajn","Haddock"); /* Just for fun using macro POPULATE */
+     POPULATE(3,78,"Kaptajn","Haddock"); /* using macro POPULATE (Just for fun)*/
          /* Parse structure and print populated students */
-     for ( i=0; i < STUDENTS ; i++ ) {
+     for ( i = 0; i < STUDENTS ; i++ ) {
          if ( class[i].id != FREE ) {
                  printf("Student: ID: %i name: %s %s\n",class[i].id, class[i].name, class[i].surname);