No memory is allocated for the char[] as no size is specified. Specify a size for the char[]. Also branchcode should be int, not int[].
in user.h :
Code:
char name[];
char surname[];
char bank[];
char branch[];
int branchCode[];
...
char company[];
change to
Code:
char name[21];
char surname[21];
char bank[21];
char branch[21];
int branchCode;
...
char company[21];
in user.cpp
Code:
void User::getBranchCode()
{
input(19,3,branchCode,21);
}
change to
Code:
void User::getBranchCode()
{
input(19,3,&branchCode,21);
}