Get unlimited char in Cpp

Question

I want to get unlimited chars, actually I created char*, I use cin for it, and I want to change it to string. I don't know the length of the input which user enters, so I made this solution for myself. Can someone tell me plz, how to get a char* without knowing the size of input and converting to string. thanks.

You could create a linked list. But that's way less efficient over time than what std::string does, which is hold some buffer that begins at an initial size, and then reallocates a larger buffer when it gets too big. — AndyG, Jun 28 '17 at 12:23
Actually I Want another solution , not getting string, I wanna solve my problem in getting unlimited char,is there anyway except linkedlist? — Zahra, Jun 28 '17 at 12:29
@Zahra Alternatively you could use a `std::unique_ptr s(new char[arbitrary_length]);`. But you would need to manage the NUL termination yourself, and still know a maximum length before taking input. The better way is to simply use `std::string`. — πάντα ῥεῖ, Jun 28 '17 at 12:31
If you don't want to use `std::string` then you have to implement the functionality of `std::getline` yourself. Maybe you could copy the source to your project and tinker with it. — Dialecticus, Jun 28 '17 at 12:44

Petar Velev · Answer 1 · 2017-06-28T12:35:21.533

5

Since it is C++. Just use std::string

If you really need to use char* look at this topic

edited Jun 28 '17 at 12:35

answered Jun 28 '17 at 12:21

Petar Velev

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score 2 · Answer 2 · answered Jun 28 '17 at 12:26

2

Instead of using a char *, use the standard library.

  #include <string>
  #include <iostream>

  int main()
  {
       std::string data;

       std::getline(std::cin, data);

       std::cout << data << '\n';
  }

This will read a string of any length (at least, until a newline is entered, which will not be included in data) and then print it out.

You might wish to also check the state of std::cin to test if any errors occurred.

answered Jun 28 '17 at 12:26

Peter

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Thank you a lot @Peter , but actually I'm searching for the way which I can get char. thank you for your reply! – Zahra Jun 28 '17 at 12:33
1

@Zahra - Read the documentation for `std::string`. It has member functions that provide access to the underlying data ..... as a pointer to (the first element of) a dynamically allocated array of `char` i.e. a `const char *`. If you try to work with a raw pointer (instead of `std::string`), you'll need to manually manage the memory allocation and (just as importantly) deallocation when you no longer need it. – Peter Jun 28 '17 at 12:38

Get unlimited char in Cpp

2 Answers2