Library Functions

The library functions are provided by the system and stored in the library. The C library function is also called an inbuilt function in C programming.

To use Inbuilt Function in C, you must include their respective header files, which contain prototypes and data definitions of the function.

C program to Demonstrate the use of Library functions

Example:

  #include<stdio.h>
  #include<ctype.h>
  #include<math.h>

  void main()
  {
    int i = -10, e = 2, d = 10; /* Variables Defining and Assign values */  float rad = 1.43;
    double d1 = 3.0, d2 = 4.0;

    printf("%d\n", abs(i));
    printf("%f\n", sin(rad));
    printf("%f\n", cos(rad));
    printf("%f\n", exp(e));
    printf("%d\n", log(d));
    printf("%f\n", pow(d1, d2));    
  }

Program output:

10

0.990105

0.140332

7.389056

-1145744106

81.000000