Basic Program Structure
Part of the Fundamentals section of Coddy's C journey — lesson 4 of 63.
Every C program must start with header directives like:
#include <stdio.h> // Header for input/output
#include <math.h> // Header for math functionsThese directives include header files containing declarations for functions and objects your program uses.
All executable code must be inside the main() function, which is the entry point of the program. For example:
#include <stdio.h> // Header for input/output
int main() { // Main function
printf("This is my first C program!"); // Output statement
return 0; // Return statement - not mandatory in modern C
}Remember, every statement ends with a semicolon (;), except for code blocks in curly braces.. The semicolon is mandatory and tells C that you've reached the end of a statement.
Challenge
EasyCreate a C program with a main() function. Inside the main() function, write code to output the following text:
This is my first C program!Cheat sheet
Every C program must start with header directives:
#include <stdio.h> // Header for input/output
#include <math.h> // Header for math functionsAll executable code must be inside the main() function:
#include <stdio.h>
int main() {
printf("This is my first C program!");
return 0;
}Every statement ends with a semicolon (;), except for code blocks in curly braces.
Try it yourself
#include <stdio.h>
int main() {
// Your code here
return 0;
}
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Fundamentals
3Operators
Arithmetic OperatorsModulo OperatorIncrement/DecrementAssignment OperatorsRelational OperatorsLogical Operators Part 1Logical Operators Part 2Logical Operators Part 3Recap Challenge