How to add statement if-else? - c++

Question

How to add if-else statement for "kodeprodi"?
Everytime I add if-else statement, the message "Lvalue required" always appears.
#include <iostream>
#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
typedef struct {
char bp[13];
char nama[15];
int kodeprodi;
char namaprodi[10];
float ipk;
} mahasiswa;
int main()
{
char pil;
do {
mahasiswa mhs[10];
int i, n;
{
printf("Data Nilai Mahasiswa\n");
printf("Berapa banyak data = ");
scanf("%d", &n);
for(i = 0; i < n; i++) {
printf("Data mahasiswa ke-%d\n", i+1);
printf("Nomor BP: "); scanf("%s", &mhs[i].bp);
printf("Nama: "); scanf("%s", &mhs[i].nama);
printf("Kode Prodi: "); scanf("%d", &mhs[i].kodeprodi);
printf("IPK: "); scanf("%f", &mhs[i].ipk);
if (mhs[i].kodeprodi == 260) {mhs[i].namaprodi = "SI";}
else if (mhs[i].kodeprodi == 261) {mhs[i].namaprodi = "TI";}
}
//output
printf("No. BP Nama Kode Prodi Nama Prodi IPK \n");
for(i = 0; i < n; i++) {
printf("\n%2d %-10s %-9s %3d %3s %3.f\n",
i+1, mhs[i].bp, mhs[i].nama, mhs[i].nama,
mhs[i].kodeprodi, mhs[i].namaprodi, mhs[i].ipk);
}
}
printf("Repeat again? Y/N");
scanf("%s", &pil);
printf("\n\n");
} while ((pil == 'Y') || (pil == 'y'));
}
Even if in the statement if-else, I type like this
if(mhs[i].kodeprodi==260){namaprodi = "SI");
The error message is "Undefined symbol 'namaprodi'

Answer 1

I tweaked your code a bit. Got rid of unused conio.h, changed kodeprodi type to int (because char can only handle numbers -127..127), removed & from some scanf calls (because you should pass pointer to first character for %s formatter), deleted extra mhs[i].nama argument for printf.
Sorry, I completely didn't understood your code :-) My tweaks were semi-automatic! You should learn C programming better.
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
typedef struct {
char bp[13];
char nama[15];
int kodeprodi;
char namaprodi[10];
float ipk;
} mahasiswa;
int main() {
char pil;
do {
mahasiswa mhs[10];
int i, n;
{
printf("Data Nilai Mahasiswa\n");
printf("Berapa banyak data = ");
scanf("%d", &n);
for(i=0;i<n;i++) {
printf("Data mahasiswa ke-%d\n", i+1);
printf("Nomor BP: "); scanf("%s", mhs[i].bp);
printf("Nama: "); scanf("%s", mhs[i].nama);
printf("Kode Prodi: "); scanf("%d", &mhs[i].kodeprodi);
printf("IPK: "); scanf("%f", &mhs[i].ipk);
if(mhs[i].kodeprodi==260)
strcpy(mhs[i].namaprodi, "SI");
else if(mhs[i].kodeprodi==261)
strcpy(mhs[i].namaprodi, "TI");
}
//output
printf("No. BP Nama Kode Prodi Nama Prodi IPK \n");
for(i=0;i<n;i++) {
printf("\n%2d %-10s %-9s %3d %3s %3.f\n", i+1, mhs[i].bp, mhs[i].nama, mhs[i].kodeprodi, mhs[i].namaprodi, mhs[i].ipk);
}
}
printf("Repeat again? Y/N");
scanf("%s", &pil);
printf("\n\n");
} while ((pil == 'Y') || (pil == 'y'));
return 0;
}

Answer 2

For a quick fix, use:
if(mhs[i].kodeprodi==260){strncpy(mhs[i].namaprodi, "SI", 9);
strncpy() is needed to copy the contents into namaprodi.
namaprodi is a member of struct mahasiswa, so you can't access it directly.
But better use std::string instead.
Also, as #BoPersson mentioned, char kodeprodi; can't hold 260, so you'll better to convert that to an int.