Why Doesn\'t `getline` Prompt for Input in C ?

getline Not Prompting for Input: A Case of Buffer Issues

When using getline(cin, mystr) in C , you may encounter an issue where it doesn't prompt for user input and instead assigns the initial value of "0" to the price variable. This is because getline reads input until it encounters a newline character ('n'), and there may be a lingering newline character in the input buffer.

The problem arises when mixing input stream operators like >> with getline. When you use cin >> i to read an integer, the user's input is followed by a newline character. However, this newline remains in the input buffer. When you subsequently call getline, it interprets the newline character as the input, without prompting the user.

Possible Solutions:

• Ignore Newline Character: Before calling getline, use cin.ignore() to remove the newline character from the input buffer. For example:

cin.ignore();
getline(cin, mystr);

• Use Custom Input Functions: Write a function that reads input as a string and converts it to the desired data type, handling newline characters appropriately. For example:

int getInt() {
  string input;
  getline(cin, input);
  return stoi(input);
}

• Avoid >> for Input: Use getline exclusively for input and convert the string to the desired data type. This approach increases code safety and robustness.

Recommended Practice:

It's best practice to use getline for all input, ensuring that newline characters are handled properly and input is always prompted for. Avoid mixing >> with getline to prevent these buffer issues.

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