The First C Program

Introducing the concept of writing a simple C program to calculate simple interest.

Form of a C Program

Each instruction is a separate statement.

Statements must appear in the desired execution order.

Blank spaces for readability.

All statements in lowercase.

C is a free-form language.

Statements end with a semicolon (;).

Comments in a C Program

Comments clarify the purpose of the program or statements.

Comment format: /* comment text */

Comments are for programmer understanding.

Comments cannot be nested.

Multi-line comments allowed.

ANSI C also supports // for comments.

What is `main()`?

`main()` is a C function.

It contains a set of statements.

`main()` always returns an integer.

0 indicates success; non-zero indicates failure.

`void main()` is non-standard.

Variables and Their Usage

Variables must be declared before use.

Example: int p, n; float r, si;

Use variables in expressions.

printf() and Its Purpose

C uses `printf()` to display output.

Include <stdio.h> to use `printf()`.

`printf()` format: printf("", );

Format specifiers: %f, %d, %c.

Escape sequence: '\n' for a newline.

Examples of `printf()`

Illustrate different uses of `printf()` with examples.

Questions and Answers

Open the floor for questions.