Array of Structures in C. not linked list

Question

I am having trouble making an array of structures. I want to store data regarding multiple students and take input using the execution of the program. Then output the memory address of persons name with highest marks.

I tried getting to know the answers on similar issues on site, to no help.

The code I have written is

the struct

struct student{
    char name;
    int marks;
};

and the function is

int num,max = 0,i;
    printf("Number of students?\n");
    scanf("%d", &num);
    struct student* students = (struct student*)malloc (num* (sizeof(struct student)));
    for (int x = 0; x < num; x++)
    {
        printf("Enter Name\n");
        scanf("%c" , &students[x].name);
        printf("Enter Marks\n");
        scanf ("%d" , &students[x].marks);
    }   
    for (i = 1; i < num; i++)
    {
        if (students[max].marks<students[i].marks)
        {
            max = i;
        }
    }
    printf("The Memory Add for %c is %p\n", students[max].name , &students[max].name );

It is a part of menu driven program. It goes into a weird loop after line 5 in function code. And i can't create a doubly linked list for the same.

Edit 1

These are the changes i made to struct and func

struct student{
    char name[20];
    int marks;
};


void memadd(){
    int num,max = 0,i, mark;

    printf("Number of students?\n");
    scanf("%d", &num);
    struct student* students = (struct student*)malloc (num* (sizeof(struct student)));
    for (int x = 0; x < num; x++)
    {
        printf("Enter Name\n");
        scanf("%s" , &students[x].name);

        printf("Enter Marks\n");
        scanf ("%d" , &mark);
        students[x].marks = mark;
    }   
    for (i = 1; i < num; i++)
    {
        if (students[max].marks<students[i].marks)
        {
            max = i;
        }
    }
    printf("The Memory Add for %s is %p\n", students[max].name , &students[max].name );

It is giving an array at input of the name. "format specifies type 'char ' but the argument has type 'char ()[20]'"

How do I make the format to be char * [20]?

Edit 2 The final working code after correcting the char name to being a character array And issue with scanning of names.

struct student{
    char name[20];
    int marks;
};
int num,max = 0,i, mark;

    printf("Number of students?\n");
    scanf("%d", &num);
    struct student* students = (struct student*)malloc (num* (sizeof(struct student)));
    for (int x = 0; x < num; x++)
    {
        printf("Enter Name\n");
        scanf("%19s" , students[x].name);

        printf("Enter Marks\n");
        scanf ("%d" , &mark);
        students[x].marks = mark;
    }   
    for (i = 1; i < num; i++)
    {
        if (students[max].marks<students[i].marks)
        {
            max = i;
        }
    }
    printf("The Memory Add for %s is %p\n", students[max].name , &students[max].name );

However, what if I wish to print the address in Hex numbers? or the one that am getting is hex already.? Because I got an output of The Memory Add for XYZ is 0x7fb340c03928

Is the first entry in your struct char name? That certainly should be an array of chars, e.g. char name[80], which should then be scanned with %s, or better yet, %79s. — M Oehm
– M Oehm, Commented May 20, 2014 at 18:32
You must remove the &, because the array name already points to the address of the first element. — Olaf Dietsche
– Olaf Dietsche, Commented May 20, 2014 at 18:51

Olaf Dietsche · Accepted Answer · 2014-05-20 18:47:35Z

2

The problem is with the student name being a char and

scanf("%c" , &students[x].name);

What happens is, you read in the number of students with

scanf("%d", &num);

Now you have read num, but there is still a newline in the input buffer. Then you try to read a character with %c, but this reads the remaining newline.

When you change the student's name to a character array, e.g.

struct student{
    char name[20];
    int marks;
};

and read the name with

scanf("%19s" , students[x].name);

it will skip the remaining whitespace/newline and read the name as it should.

answered May 20, 2014 at 18:47

Olaf Dietsche

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