“ char”类型的参数与char *类型的参数不兼容

Question

I keep receiving this error and unsure how to fix it. I'm new to C programming and tried searching through the book/internet and couldn't find much help. I'm trying to create a program that will print a grade report using a loop and a sctructure

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct Grades
{
    char Name[20];
    char Hrs;
    int ID;
    char ClassName[20];
    char Grade;
    char ClassID[6];
};

int main ()
{
    struct Grades Transcript[6];
    int classCnt = 0;
    int vHrs=0;
    char vGrade[2];
    char vName[20], vCID[6], vClassName[20];

    printf("Enter Students Name: ");
    fgets(vName, 20, stdin);

    do
    {   printf("Enter Class ID; ");
        fgets(vCID, 6, stdin);
        strcpy_s(Transcript[classCnt].ClassID, vCID);
        printf("Enter Class Name: ");
        fgets(vClassName, 20, stdin);
        strcpy_s(Transcript[classCnt].ClassName, vClassName);
        printf("Enter Class Hours: ");
        scanf("%d", &vHrs);
        strcpy(Transcript[classCnt].Hrs, vHrs);         //Problem occurs here
        printf("Enter Class Grade: ");
        scanf("%c", vGrade);
        strcpy(Transcript[classCnt].Grade, vGrade);     //Problem occurs here
        classCnt++;
    }while(classCnt<=6);
}

Answer 1

You actually have a number of problems here:

First, strcpy() is used to copy a string, if you have a character and you want it to assign it, you can simply assign it with the = operator. The strcpy() function is used when you have a character array you want to assign.

So your first problem

strcpy(Transcript[classCnt].Hrs, vHrs);

Hrs from your struct is just a char type, and vHrs is an int type. You can simply assign it like:

Transcript[classCnt].Hrs = vHrs;

However, an int can hold a lot more data than a char can, this is going to give you a warning about overflow and you should listen to it (depending on the implementation char holds -128 to 127, where as int holds −2,147,483,648 to 2,147,483,647). Decide what data type you really wanted here and either make Hrs an int or vHrs a char then just do the assignment.

Second problem:

scanf("%c", vGrade);

vGrade as a character array (it is made up of more than one character) that means you should assign it with the string format operator "%s" , but when you do a string you should make the array long enough for the number of characters you want + 1 (for the NULL terminator).

Third problem:

strcpy(Transcript[classCnt].Grade, vGrade);

Grade is a char whereas vGrade is an array. Again, you have to make a decision of type, if you wanted a "string" of characters then you need to make them both arrays, if you wanted just a single character then change the type of vGrade and do a simple assignment with the = operator.

Answer 2

The thing you're running into here is a data typing error.

The structure member .Hrs is of type "char" . The argument to strcpy is a "char *" . Think of it like this: A char is a single 8 byte number representing a value in ASCII. A "char *" is a pointer to an array of characters (or a string in C language).

The Above is traditionally true,but , today it might be a unicode or multi-byte character string, as well. In either case, what you need is the assignment operator ( = ), not a strcpy .

So you're telling strcpy to look at a single value ( char ), not a string of values ( char * ) which is it expecting as it's argument. In this case, you can just copy the value of the integer you scanned in with scanf directly.

Transcript[classCnt].Hrs = vHrs;

and

Transcript[classCnt].Grade = vGrade;

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