cin and cout are streams and do not exist in C. You can use printf() and scanf() in C. In general running C code in C++ will work as C++ is based on C but going the other way can be problematic as there are a lot of features in C++ that don't exist in C.
cin and cout aren't applicable to c language because of the conflicting header statement . if using c use printf in place of cout and scanf for cin.
The usage of cin is simple, too, and as cin is used for input, it is accompanied by the variable you want to be storing the input data in: std::cin >> Variable; Thus, cin is followed by the extraction operator >> (extracts data from the input stream), which is followed by the variable where the data needs to be stored.
cin is an object of the input stream and is used to take input from input streams like files, console, etc. cout is an object of the output stream that is used to show output. Basically, cin is an input statement while cout is an output statement. They also use different operators.
The "c" in cout refers to "character" and "out" means "output". Hence cout means "character output".
The cout command is a data stream which is attached to screen output and is used to print to the screen, it is part of the iostream library.
std::cout handles all types for you, while printf requires specific syntax depending on an integer type (there are non-integer types, but the only non-integer type you will use in practice with printf is const char * (C string, can be obtained using to_c method of std::string )).
get() is used for accessing character array. It includes white space characters. Generally, cin with an extraction operator (>>) terminates when whitespace is found.
std:cout: A namespace is a declarative region inside which something is defined. So, in that case, cout is defined in the std namespace. Thus, std::cout states that is cout defined in the std namespace otherwise to use the definition of cout which is defined in std namespace.
The cin object in C++ is an object of class iostream. It is used to accept the input from the standard input device i.e. keyboard. It is associated with the standard C input stream stdin. The extraction operator(>>) is used along with the object cin for reading inputs.
The cin and cout keywords are very popular in C++. They are used for taking inputs and printing outputs, respectively. To use them, you must include iostream header file in your program.
The modulo operator, denoted by %, is an arithmetic operator. The modulo division operator produces the remainder of an integer division. Syntax: If x and y are integers, then the expression: x % y.
You can print all of the normal C types with printf by using different placeholders: int (integer values) uses %d. float (floating point values) uses %f. char (single character values) uses %c.
And the test results shown that for ints, cin and cout are equally fast (and sometimes even faster) than scanf, printf.
Tl;Dr: Both functions do the same thing but use a different backend I/O. scanf is from a previous form of c and causes more work if you change a variable type later. cin doesn't require the variable type to be added to the call to avoid this issue. scanf is typically faster than cin due to syncing.
Thus, cin means "character input". The C++ cin object belongs to the istream class. It accepts input from a standard input device, such as a keyboard, and is linked to stdin, the regular C input source. For reading inputs, the extraction operator(>>) is combined with the object cin.
int first , second , third; cout<<"enter the first number: "; cin>>first; cout<<"enter the second number: "; cin>>second; cout<<"enter the third number: "; cin>>third; cout<<float average=(first+second+third)/3; c++ variable-declaration.
To answer your question, printf is faster.
This may happen because std::cout is writing to output buffer which is waiting to be flushed. If no flushing occurs nothing will print. So you may have to flush the buffer manually by doing the following: std::cout.
Cout is used with the insertion operator, which is written as << (two “less than” signs). The actual output then follows, written within quotation marks. The line must end with a semicolon. Become familiar with other uses of cout.
We can use endl in C++ but not in C. So endl runs well in C++ but if we use C, it runs error.
It is possible to implement all of the features of ISO Standard C++ by translation to C, and except for exception handling, it typically results in object code with efficiency comparable to that of the code generated by a conventional C++ compiler.
+= Add AND assignment operator. It adds the right operand to the left operand and assign the result to the left operand. C += A is equivalent to C = C + A.