Introduction - C Programming

pre-processor : #include;the main work of pre-processor is to initialize the environment of program, i.e to link the program with the header file <stdio.h>.

header file:collection of built-in functions

main() function:program execution starts 

c input output functions:

printf() function returns the number of characters printed by it

int i = printf("studytonight");

in this program i will get 12 as value, because studytonight has 12 characters.

scanf() returns the number of characters read by it.

getchar() function reads a character from the terminal and returns it as an integer.reads only single character at a time

putchar() function prints the character passed to it on the screen and returns the same character. this function puts only single character at a time

gets() function reads a line from stdin into the buffer pointed to by s until either a terminating newline or eof (end of file). 

puts() function writes the string s and a trailing newline to stdout.