Should I use Cin or Scanf in C++? cin is the standard input stream in C++ and is generally preferred over scanf for input in C++ programs. cin is part of the C++ standard library and is designed to work seamlessly with the C++ language, including features such as object-oriented programming and exception handling.
There are already many blog posts that compares performance of cin, cout (with ios::sync_with_stdio(false) of course) vs printf, scanf. And the test results shown that for ints, cin and cout are equally fast (and sometimes even faster) than scanf, printf.
The scanf() function in C++ is used to read the data from the standard input ( stdin ). The read data is stored in the respective variables. It is defined in the cstdio header file.
By default, cin / cout waste time synchronizing themselves with the C library's stdio buffers, so that you can freely intermix calls to scanf / printf with operations on cin / cout .
printf is a predefined function which is in c language in stdio header file. While cout is a predefined function in c++ language which is in iostream header file. Now, both scanf and cin is used to take input from the user.
cin uses operator overloading to allow you to input data in a more intuitive and readable way, using the >> operator to extract data from the stream. scanf , on the other hand, uses a formatting string to specify how the data should be read.
cin is not a statement, it's a variable that refers to the standard input stream. So the closest match in C is actually stdin .
Ans: The Limitations of scanf() are as follows: scanf() cannot work with the string of characters. It is not possible to enter a multiword string into a single variable using scanf(). To avoid this the gets( ) function is used. It gets a string from the keyboard and is terminated when enter key is pressed.
In the scanf() function there is a problem with buffer overflow. Buffer overflow is a problem it occurs when the size of the information written in a memory location exceeds the memory limit that is allotted to it. In simple words, it is a problem of excessive input than the allocated memory of a declared variable.
Answer: Yes. Printf can be used in C++. To use this function in a C++ program, we need to include the header <cstdio> in the program.
You can safely scan numeric values using the strto*() functions: strtol() , strtoll() , strtoul() , strtoull() , strtof() , strtod() , strtold() . Their behavior on errors is a bit tricky, but at least it's well defined. Good answer.
fgets() or gets() is a good alternative to scanf(),as it can accept incorrect input and allows the complier to execute the rest of the program. Yes there are but scanf is more effective. You can use getc for taking input as Character. And you can use gets for getting string as input.
The C++ version of scanf is std::scanf and can be found in the <cstdio> header. Yes, it's the same function - because C functions can also be used in C++. Yes and printf also can be used in C++...but nobody uses it.
Yes. C++ is great for competitive programming. It is one of the most popular programming languages for competitive programming.
C++ is the most preferred language for competitive programming mainly because of its STL. Short for Standard Template Library, the STL is a collection of C++ templates to help programmers quickly tackle basic data structures and functions such as lists, stacks, arrays, etc.
Most competitive programmers prefer C++ over C because of the in-built functions associated with it. In C++, you can simply use sort(a, a+n) to sort an array a[] of size n, or use lower_bound(a, a+n, num) to binary search a number instead of writing the entire code (imagine the benefits in a time bound contest).
The reason scanf is unsafe is that you can use %s as a format string and have a buffer overflow because there's no limit on what it will read. You should always use a width specifier like %99s .
Warning: The sprintf function can be dangerous because it can potentially output more characters than can fit in the allocation size of the string s . Remember that the field width given in a conversion specification is only a minimum value. To avoid this problem, you can use snprintf or asprintf , described below.
It's not needed. char s[1234]; scanf("%s", s);
Lacks Constructor and Destructor
C doesn't have any object-oriented functionalities, and hence, it doesn't have Constructor and Destructor features. So in C Language, you need to carry out the manual construction and/or destruction of the variable, either by utilizing a function or by different means.
If the input contains spaces or newlines before the expected input, scanf() might skip over them and not take input. To fix this, you can use the %*c specification to read and discard any whitespace characters before the next input.
The difference between scanf("%c", &c1) and scanf(" %c", &c2) is that the format without the blank reads the next character, even if it is white space, whereas the one with the blank skips white space (including newlines) and reads the next character that is not white space.
The cin. ignore() function is used which is used to ignore or clear one or more characters from the input buffer.
Well, you use cin inside a while loop when you need the user to enter a value that will be used after that, in the same loop. Everytime the loop runs, the user can chose something else. For example, calculating x*y.
Return Value of cin.
The return value of the cin. get() in the C++ function is the first string from the user input. The function waits until the user enters the input. And after pressing the enter key, the function returns the first string from the user-provided input.