Is it possible to run a program without including the header files? If yes, then how ? And then why to include the header files?

Answer 1

Yes it is possible.. but if u want to use methods within the header files then u must include that header file

But main() is important don't forget to add that..

Happy learning ☺️..
by the way it is a good question ☺️

Answer 2

It is possible, if you use the C preprocessor:

https://code.sololearn.com/cGyoXq0ebQGz/?ref=app

Answer 3

We use header files to access predefined library functions..

Suppose if you want to print something on screen with printf() function then you have to include header files <stdio.h> because it is stored in header files ..if you don't want to include header file then you can use std :: . Similarly <conio.h> this header file is used to access functions like clrscr () and getch () . Also we have lots of other header file MATH.H STRING.H you can use it according to your requirement.

Answer 4

the Header files are used to make your programming experience easier

For example: you must include <string.h> to use this function
strlen("hello world") which calculates the number of characters in the string
But you can do that without using this function and including<string.h>

You can do that by making your own function as you can see:

#include <iostream>
using namespace std;
int stringlength(string s)
{int counter=0;
for (int i=0;i>=0;i++)
{
if(s[i]>='A'&&s[i]<='z'||s[i]==' ') // s[i]=='space'
counter ++;
else break;}
return counter;
}
int main()
{
cout<<stringlength ("hello world");
} (I included iostream and used cout because i don't know how to create cout but i think it's something related to classes and these stuff)

Or you can just write

#include <iostream>
#include <string.h>
using namespace std;
int main()
{
cout<<strlen("hello world")
}
And you'll get the same output much easier
Hopefully i answered your question

Answer 5

Sonic extern indicates the compiler that printf has C-linkage..
C links against the standard library by standard and finds a match for the function signature provided so everything works..
In fact if it were a c code you could omit to #include the cstdlib.

Answer 6

Michael what does extern "C" actually do?

Answer 7

Well I wanna give a good point what header file has is DECLARATIONS of all the important functions you're going to use but it doesn't have the source code for them