computer programming

computer programming basic but important information 

1.why do we use #include<stdio.h> in c programming?

   ⇒standard input output header file(stdio.h) is a header file.It is included at the top as             #include<stdio.h>so that we can use the functions like printf,scanf,etc.if #include<stdio.h> is not included at the top the use of scanf and printf is invalid.

2.why do we use #include<conio.h> ?

⇒ it is also a header file (consol input output.header file ).it is included at the top so that we can use clrscr() ,getch(),kbhit,etc.
       

3.why do we use int main?

 ⇒ int main is the special ,main function that tells the compiler from where the program starts.
    this main function can be used as int main,void main.
    the difference between int main and void main is that if int main is used, the program at last ask for return0; but if void main is used there is no need  to use return 0; at the end.

• we can write return 0 as  return 0;  , return (0);

     4. why do we use clrscr()?
⟹ clear screen [clrscr()] is use to clear output screen before program execute.