Question

Why does the same program giving different outputs when inputs are given through different methods?

Program 1:

int main(){
    char s[10];
    cout << "Enter a String\n";
    cin >> s;
    cout << "The entered String is\n";
    cout << s << "\n";
    return 0;
}  

When I give input through command line “Hello World”, the output I’m getting is only “Hello”

Program 2:

int main(){
    char s[] = "Hello World";
    cout << "The entered String is\n";
    cout << s << "\n";
    return 0;
}  

In this case, I’m getting output of “Hello World”.

What is the difference between both programs? Is the logic the same? How can I obtain the whole string “Hello World” when entered through the command line? Is there a way?

Answer 1

Use getline():

string s;
getline(cin, s);
cout << "The entered String is\n";
cout << s << "\n";

The problem with your code is that the input stream extraction operator >> only gets characters up to the next whitespace (so, just one “word”). The getline() function gets the whole line.