freeCodeCamp/guide/english/c/hello-world/index.md

39 lines
1.6 KiB
Markdown
Raw Normal View History

2018-10-12 19:37:13 +00:00
---
title: Hello World C
---
## Hello World
2018-11-06 14:05:57 +00:00
Probably the first line of text that everyone prints out on the console when one begins his/her remarkable jouney of this endless programming world.
2018-10-12 19:37:13 +00:00
To write on console you can use the function `printf()` contained in the library `include <stdio.h>`
```C
#include <stdio.h>
int main(void)
{
2018-11-06 14:05:57 +00:00
printf("Hello World!\n"); //lines starting with this are called comments..
2018-10-12 19:37:13 +00:00
return 0;
}
```
## Explanation
* The #include <stdio.h> is a preprocessor command. This command tells compiler to include the contents of stdio.h (standard input and output) file in the program.
2018-11-14 12:31:18 +00:00
* The stdio.h file contains functions such as scanf() and printf() to take input and display output respectively.
2018-10-12 19:37:13 +00:00
* If you use printf() function without writing #include <stdio.h>, the program will not be compiled.
* The execution of a C program starts from the main() function.
* The printf() is a library function to send formatted output to the screen. In this program, the printf() displays Hello, World! text on the screen.
* The \n in printf creates a new line for the forthcoming text.
2018-10-12 19:37:13 +00:00
* The return 0; statement is the "Exit status" of the program. In simple terms, program ends with this statement
## Output:
```
2018-11-06 14:05:57 +00:00
>Hello World!
2018-10-12 19:37:13 +00:00
```
#### More Information
* Conventionally, the first ever program you write is the "hello world" program, be it in any language.
* This is because Brian Kernighan was the first to write "hello, world" program for the documentation of the BCPL programming language developed by Martin Richards.