C++ - Reading a line without getline [duplicate] - c++

Question

This question already has an answer here:
C++ - overloading operator >> for my string class
(1 answer)
Closed 9 months ago.
I am trying to read user entered data from the stream and then store it in a custom String class.
To my best knowledge, std::getline() can route data only to std::string , that is why I need to come up with something else, as my project is not allowed to use std::string class.
My code looks like this:
String street();
std::cout << "Street: "; std::cin >> std::noskipws;
char c='\0';
while(c!='\n'){
std::cin >> c;
street=street+c;
}std::cin >> std::skipws;
int bal=0;
std::cout << "Balance: "; std::cin >> bal;

Answer 1

To my best knowledge, std::getline() can route data only to std::string , that is why I need to come up with something else, as my project is not allowed to use std::string class.
Note that std::getline and std::istream::getline are two separate functions. The former will work with std::string while the latter will work with C-style strings (i.e. sequences of characters that are terminated by a null character).
Therefore, if you are not allowed to use std::string, then you can still use std::istream::getline, for example like this:
char line[200];
String street;
std::cout << "Street: ";
if ( std::cin.getline( line, sizeof line ) )
{
//the array "line" now contains the input, and can be assigned
//to the custom String class
street = line;
}
else
{
//handle the error
}
This code assumes that your custom class String has defined the copy assignment operator for C-style strings.
If it is possible that the lines will be larger than a fixed number of characters and you want to support such lines, then you could also call std::istream::getline in a loop:
char line[200];
String street;
std::cout << "Street: ";
for (;;)
{
std::cin.getline( line, sizeof line );
street += line;
if ( std::cin.bad() )
{
//TODO: handle error and break loop, for example by
//throwing an exception
}
if ( !std::cin.fail() || std::cin.eof() )
break;
std::cin.clear();
}
This code assumes that operator += is defined for class String.
This loop will continue forever until
getline succeeds (i.e. it is able to extract (but not store) the newline character), or
end-of-file is reached (eofbit is set), or
an error occurs (badbit is set).

Answer 2

You can use the C function "getchar()" to read a single character from standard input. This link describes it: https://www.ibm.com/docs/en/i/7.3?topic=functions-getc-getchar-read-character.
Here is my code:
String street=();
std::cout << "Street: ";
char c='\0';
while(c!='\n'){
c = getchar();
street=street+c;
}
int bal=0;
std::cout << "Balance: "; std::cin >> bal;
cout << street << endl;
I hope this will help you, and I recommend you make an independent function that will read line from standard input and whose return type will be "String". You can declare it as:
String readLine();
And I also recommend you to pay attention to that while loop because string that is obtained from that loop will have character '\n' at the end of it.