如何在不使用C语言的头文件的情况下编写Hello World

Question

How to write hello world without using header files in C?

#include<conio.h>
#include<stdio.h>

void main(){

printf("Hello World");
getch();

}

This is simple C program with header file...

• conio.h - for console
• stdio.h - is used for printf and scanf

Answer 1

You need header files primarily because of the prototype declaration of library functions plus any necessary types and additional macros needed to facilitate their use. They are provided in form of header files for ease of re-use.

In your case, you can write the prototypes on your own and you should be okay Something like

/*  Prototypes on your own */
int getchar(void);
int printf(const char *format, ...);
int puts(const char *s);

int main(void) {  //this is the prescribed signature for hosted environment
    //printf("Hello World\n");    //not good to use printf if don;t need conversion
    puts("Hello World");
    //getchar();
    return 0;
}

should do just fine.