Difference between revisions of "C programming/Structures"
From Teknologisk videncenter
m (→Example 2) |
m (→Example 3) |
||
| Line 60: | Line 60: | ||
typedef struct coor coordinate; | typedef struct coor coordinate; | ||
int main( void ) { | int main( void ) { | ||
| − | coordinate *place = malloc(sizeof(coordinate)); | + | coordinate *place = malloc( sizeof( coordinate ) ); |
| − | + | ||
(*place).x = 17; /* One form of indirect addressing shown */ | (*place).x = 17; /* One form of indirect addressing shown */ | ||
place->y = 19; /* Another form of indirect addressing shown */ | place->y = 19; /* Another form of indirect addressing shown */ | ||
| − | + | ||
| − | printf("Tallet er %i\n",place->x+place->y); | + | printf("Tallet er %i\n",place->x + place->y); |
| − | return(0); | + | free( place ); /* Always remember to free allocated memory (Good habbit)*/ |
| + | return( 0 ); | ||
} | } | ||
| − | |||
</source> | </source> | ||
[[Category:C]] | [[Category:C]] | ||
Revision as of 14:27, 21 November 2010
Basic structrues
Example 1
Create and instantiate a structure
#include <stdio.h>
#include <stdlib.h>
struct coor {
int x;
int y;
};
int main( void ) {
struct coor place;
place.x = 17;
place.y = 19;
printf("Tallet er %i\n",place.x+place.y);
return(0);
}
Example 2
Same as example 1, but using as typedef
#include <stdio.h>
#include <stdlib.h>
struct coor {
int x;
int y;
};
typedef struct coor coordinate;
int main( void ) {
coordinate place;
place.x = 17;
place.y = 19;
printf("Tallet er %i\n",place.x+place.y);
return(0);
}
Example 3
In example 3 the memory is reserver with malloc and indirect addressing is used to access the structure.
#include <stdio.h>
#include <stdlib.h>
struct coor {
int x;
int y;
};
typedef struct coor coordinate;
int main( void ) {
coordinate *place = malloc( sizeof( coordinate ) );
(*place).x = 17; /* One form of indirect addressing shown */
place->y = 19; /* Another form of indirect addressing shown */
printf("Tallet er %i\n",place->x + place->y);
free( place ); /* Always remember to free allocated memory (Good habbit)*/
return( 0 );
}