I have run into a problem or maybe I am just doing something wrong since I am new to C and structs. I want to take a text file such as this:
3
Trev,CS,3.5
Joe,ART,2.5
Bob,ESC,1.0
and read in the first line as the number of students then from there out gather student info and put them in a struct called StudentData:
typedef struct StudentData{
char* name;
char* major;
double gpa;
} Student;
Where I run into a problem is after I seemingly assign the data to an individual struct, the struct data becomes mixed up. I have commented out exactly what is going on (or at least what I believe is). Hopefully it isn't painful to read.
main(){
int size, i;
char* line = malloc(100);
scanf("%d\n", &size);//get size
char* tok;
char* temp;
Student* array[size]; //initialize array of Student pointers
for(i = 0; i<size;i++){
array[i] = malloc(sizeof(Student));//allocate memory to Student pointed to by array[i]
array[i]->name = malloc(50); //allocate memory for Student's name
array[i]->major = malloc(30);//allocate memory for Student's major
}
for(i = 0; i<size;i++){
scanf("%s\n", line);//grab student info and put it in a string
tok = strtok(line, ","); //tokenize string, taking name first
array[i]->name = tok;//assign name to Student's name attribute
// printf("%s\n",array[i]->name);//prints correct value
line = strtok(NULL, ",");//tokenize
array[i]->major = line;//assign major to Student's major attribute
// printf("%s\n",array[i]->major);//prints correct value
temp = strtok(NULL, ",");//tokenize
array[i]->gpa = atof(temp);//assign gpa to Student's gpa attribute
// printf("%.2f\n\n",array[i]->gpa); //prints correct value
}
for(i=0;i<size;i++){ //this loop is where the data becomes jumbled
printf("%s\n",array[i]->name);
printf("%s\n",array[i]->major);
printf("%.2f\n\n",array[i]->gpa);
}
}
The output looks like this:
Trev
Joe
3.50
Joe
Bob
2.50
Bob
ESC
1.00
I can't really understand what is going on in the memory between assigning values and printing them.