5
C is an extremely small language. Many of the functions of other languages are not included in C. e.g. No built in I/O, string handling or mathematical functions.
What use is C then?
C provides functionality through a rich set of function libraries.
As a result most C implementations include standard libraries of functions for many facilities ( I/O etc.).
You must include these libaries to utilize their functions such as:
#include <stdio.h>
#include <math.h>
main()
{
}
A programmer can also develop his/ her own function libraries and also include special purpose libraries (e.g. NAG, PHIGS).