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How does `cin` handle input in C and why is `getline()` preferred for reading entire lines?
How does `cin` handle input in C and why is `getline()` preferred for reading entire lines?
Oct 30, 2024 am 09:12 AM
C Input Stream Behavior with "cin"
When reading input using the "cin" stream in C , it's important to understand how it interacts with various data types. By default, "cin" reads a word at a time, which can lead to unexpected behavior when dealing with character arrays or strings.
In the provided code example, the "input()" method in the "String" class uses "cin >> str;" to read the input string. However, this statement only captures a single word, ignoring any subsequent words in the input. As a result, when the input contains multiple words, such as "steve hawking," only the first word, "steve," is stored in the "str" array.
Solution: Using getline() to Read Complete Lines
To read a complete line of input into a character array, the "getline()" function can be used instead of "cin >>". Here's the updated input method using "getline()":
<code class="c++">void input()
{
cout << "Enter string :";
cin.getline(str, sizeof str);
}"getline()" takes two arguments: a pointer to the destination array and the size of the array. It reads input until a newline character is encountered, effectively capturing the entire line of input.
Additional Considerations
It's worth noting that using character arrays for string manipulation can be cumbersome and error-prone. The C Standard Library provides the "std::string" class, which offers a more robust and type-safe approach to string handling. Instead of using character arrays, the code could be rewritten as:
<code class="c++">#include <iostream>
#include <string>
class String
{
public:
std::string str;
void input()
{
cout << "Enter string :";
std::getline(std::cin, str);
}
void display()
{
std::cout << str;
}
};</code>
Finally, the use of header files like "iostream.h" and "conio.h" is outdated. Modern C development should use header files such as "iostream" and "conio," respectively.
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