C Syntax
Syntax is the set of rules that decides whether your C code is written correctly. Learning the shape of a C program early makes every later topic easier.
Every C program follows the same basic structure. Once you can recognize the pieces, you will be able to read almost any small C program even before you understand every detail.
The standard structure
#include <stdio.h>
int main() {
printf("Hello, World!");
return 0;
}Breaking It Down
Statements and Semicolons
In C, most instructions are called statements, and every statement ends with a semicolon. Forgetting the semicolon is the most common beginner mistake and will stop your program from compiling.
Several statements
#include <stdio.h>
int main() {
printf("Line one");
printf("Line two");
return 0;
}- C is case sensitive, so main and Main are not the same.
- Statements run in order, from top to bottom.
- Whitespace and blank lines are ignored, so use them to keep code readable.
- Every opening brace { must have a matching closing brace }.
Note: The return 0; line uses the number zero to mean success. A different number would signal that something went wrong.
Note: If the compiler reports an error on a certain line, also check the line just above it. A missing semicolon is often noticed one line later than where it belongs.
Exercise: C Syntax
What must appear at the end of most C statements?
