I have this basic program:
#include<stdio.h>
int main() {
printf("Hello, world!");
return 0;
}
but how can I saw the compiler said: Hello, world!
and how can I start it?
sorry if it's simple but I'm new.
If you're using any UNIX (Linux/Mac) machine it's pretty simple:
You open up the terminal in the folder your program is located.
For example you type in gcc "program_name.c" -o "program_name" to compile the program
And now you have to execute the program in the terminal typing this ./"program_name"
you can put whatever you like in the "program_name" :)
I typed this program on code blocks but it is showing error on int main line
Here's the program
#include <stdio.h>
int main()
{
printf("Hello");
return 0;
}
The message return is " multiple definition of main"
The sample code is correct. It might be an IDE configuration error. Use gcc to compile your code on Linux and on Windows you can install MinGW and execute from a command window.
This is an extremely weird question, but I am still curious. I have a source code a.c, in it, I have some magic code that compiles a different code b.c in the same directory. Hence, during runtime, b.c is compiled and perhaps ran.
I apologize for this question to be vague, but is this something that's been done before? If not, is there any way to do so?
a.c:
#include <stdio.h>
int main() {
puts("a: compiling b.c");
system("gcc -o b b.c");
puts("a: executing b");
system("./b");
puts("a: done");
return 0;
}
b.c:
#include <stdio.h>
int main() {
puts("b: hello world");
return 0;
}
output:
a: compiling b.c
a: executing b
b: hello world
a: done
Yes, you can fork and exec to run the compiler, and then fork and exec again to run the compiled code. The other option is to use the system function to run the compiler, and then call system again to run the compiled code.
I wrote little program to print "Hello world" in C. I'm not a C programmer, but I liked to try it. In my program there is an error. Please tell me what is it?
This is my program:
int main(){
printf("Hello World");
}
I wrote this with my Java Experiences. I can't find what is wrong.
You can't directly use printf() function as in Java. You should tell the compiler that you are going to use the input/output stream. You can tell it in this line:
#include <stdio.h>
and also you should enter this line at the end of the source code:
return 0;
this will tell the compiler :
"If the program succeed It will return 0 otherwise It will return any other number"
This means if your program is successful main() function will return 0. Then the compile know the program is Ok.
Then at last your complete code is:
#include <stdio.h>
int main() {
printf("Hello world");
return 0;
}
To compile this and see the word "Hello World", just save this file as a .c file and Open cmd in your program directory and type
gcc hello.c -o hello && hello
(Replace the 'hello.c' with your filename, and 'hello' with the name you want to put with your .exe file)
Remember My computer is Windows. And this compile code is for windows. If your OS is UNIX like OS. then use this code to compile:
gcc hello.c -o hello
./hello
A full hello world program in C:
#include <stdio.h>
int main(void) {
printf("Hello World\n");
return 0;
}
Then compile (assuming gcc) and execute it:
gcc -o test test.c
./test
First, you have to use a header file.
#include <stdio.h>
What that does is bring up a header file with a bunch of commands in them. That will make it recognize the "printf" piece of code.
Next, you have to close your program. By not having a closing statement, the program will not compile because it doesn't know if that is the end of the code. Use this at the end of your program...
return 0;
That closes the program, meaning that the compiler can stop looking for other code. You may also want to look at some programming manuals (there are dozens of free online ones) to learn about the syntax.
One last thing: Most pieces of C code require a semicolon at the end. This is not true for the "int main" statement, nor is it for the header file which I have defined above. The "return" function that closes the program, does however, need a semicolon.
Hoped this helped.
Should also include a pause at the end:
#include <stdio.h>
int main(void) {
printf("Hello World\n");
//Read a character from the console
getchar();
return 0;
}
Just like import in Java programs, in here you have to include libraries you're using in your program. You have used library function printf, but not included stdio.h.
I agree there are many ways to write one of the simplest way is
#include<stdio.h>
int main(void){
printf("Hello World\n");
return 0;
}
You can even use different ways as suggested above.
You should first look at the structure of "main". Try to understand the various parts as already explained so well in the above answers.
"#include" : The preprocessing directives to be included in the program. But why? Because you are trying to use the functions defined inside them.
int : The return type of "main" program. But why? Because the function calling "main" needs to know if the "main" program has functioned correctly.
main : The entry point of your code. Dont ask why here :-)
main( void ) : To tell the compiler that we are not passing any arguments to program "main"
return 0 : Beacuse you promised "main" that you will return something if "main" will function properly.
Finally the code:
#include <stdio.h>
int main( void )
{
printf( "Hello World\n" ) ; //Notice the '\n' here. Good coding practice.
return 0 ;
}
#include <stdio.h> //Pre-processor commands<br/>
void main() //Starting point of the program<br/>{ //Opening Braces
printf("Hello World\n"); //Print Hello World on the screen<br/>
return 0;
} //Ending Braces
Check it once it will work, I have written it with comments:
#include<stdio.h> //Pre-processor commands
void main() {
printf("Hello World\n"); //Print Hello World on the screen
}
A full hello world program in C:
#include <stdio.h>
int main(void) {
printf("Hello World\n");
return 0;
}
Then compile (assuming gcc) and execute it:
gcc -o test test.c
./test
You can't use printf() function as in Java. You have to tell the compiler what you are going to use.
You can tell this as follows:-
#include <stdio.h>
You must enter this line in last:-
return 0;
Then Your complete code is:-
#include <stdio.h>
int main(){
printf("Hello World");
return 0;
}
For compiling this and see the word "Hello World", just save this file as a .c file and Open cmd in your program directory and type:-
gcc hello.c -o hello && hello
(Replace the 'hello.c' with your filename, and 'hello' with the name you want to put with your .exe file)
Remember My computer is Windows. So I can compile only for Windows OS.
#include <stdio.h>
int main() {
// printf, used to print (display) Hello World
printf("Hello World ! ");
// return 0, as the main function is of type int so it must return an integer value
return 0;
}
I am trying to learn C and I have just installed Xcode on my Mac. I wanted to run the first program that was already written
#include <stdio.h>
int main(int argc, const char * argv[])
{
// insert code here...
printf("Hello, World!\n");
return 0;
}
and got build failed.
I created a program in C. The libraries have been downloaded.
Thanks
Are you trying to learn C or Objective-C? As far as I know, XCode is only appropriate for Objective C.
Also, can you post your compiler error, that will help alot.