C++ Standard library functions or C++ Library functions are built-in functions in
C++ programming that will help us access functions. The prototype and the definitions
of the functions are stored in their respective header files. Therefore, to access an
inbuilt function in C++, you need to include the header file in your C++ file.
One example is the cout function that is accessible because we include the header file
library iostream on top of our program.
These are some examples of the commonly used C++ Library header files. Some of them
are based on the one in C Library, for example cstdio,
cctype, cmath, etc.
If you have prior experience in C programming, then you can include this library
in your C++ program and write C code. In simpler terms, you can use code C language
in C++ file as long as you include the library.
| C++ Header File | Description | Some Examples |
|---|---|---|
| <cassert> | Program assertion functions | assert() |
| <cctype> | Character type functions | isalnum(), isdigit(), tolower() |
| <locale> | Localization functions | use_facet, has_facet |
| <cmath> | Mathematics functions | log(), sqrt(), sin(), cos() |
| <iomanip> | Stream manipulator functions | setprecision(), setfill(), setbase() |
| <fstream> | Input/output from files functions | ifstream, ofstream |
| <string> | String handling functions | string, char_traits |
| <iostream> | Standard input/output functions | cout, cin, cerr, clog |
| <cstdlib> | Standard utility functions | abort(), exit() |
| <cstring> | C string (character array) handling functions | strcpy(), strcat(), strncat() |
| <ctime> | Date time functions | difftime(), time(), clock() |
| <cstdio> | C standard input output functions | printf(), scanf(), getchar() |