Source code
#include <stdio.h>
#include <string.h>
/*
* Program to create instances of the particles structure
*/
/* particle structure definition */
struct particle_type {
double pos [3];
double mass;
int type;
char name [80];
};
int main ( void )
{
/* create an array of three particle structures */
struct particle_type particles [3];
/* assign values to the first structure in the array */
particles[0].pos[0] = 1.1;
particles[0].pos[1] = 2.2;
particles[0].pos[2] = 3.3;
particles[0].mass = 14.2;
particles[0].type = 1;
strcpy ( particles[0].name, "neutron" );
printf ( "%s (type %d): (%.2f, %.2f, %.2f), mass %.1f\n", particles[0].name,
particles[0].type, particles[0].pos[0], particles[0].pos[1],
particles[0].pos[2], particles[0].mass );
/* copy the values from the first structure into the second and change
* the places that matter
*/
particles[1] = particles[0];
particles[1].type++;
strcpy ( particles[1].name, "proton" );
printf ( "%s (type %d): (%.2f, %.2f, %.2f), mass %.1f\n", particles[1].name,
particles[1].type, particles[1].pos[0], particles[1].pos[1],
particles[1].pos[2], particles[1].mass );
/* again copy the first one to initialize this one */
particles[2] = particles[0];
particles[2].type += 2;
strcpy ( particles[2].name, "electron" );
printf ( "%s (type %d): (%.2f, %.2f, %.2f), mass %.1f\n", particles[2].name,
particles[2].type, particles[2].pos[0], particles[2].pos[1],
particles[2].pos[2], particles[2].mass );
return ( 0 );
}
Output:
neutron (type 1): (1.10, 2.20, 3.30), mass 14.2
proton (type 2): (1.10, 2.20, 3.30), mass 14.2
electron (type 3): (1.10, 2.20, 3.30), mass 14.2
