Notice: This page requires JavaScript to function properly.
Please enable JavaScript in your browser settings or update your browser.Learn Header, Prototypes | Functions
C Basics
course content

Course Content

C Basics

C Basics

1. Introduction
Structure of the C-ProgramEssentials of C ProgramHow to Run the Program?
2. Data
DataVariablesPrintfIntroduction to ArraysTwo Dimensional ArraysChar and StringSizeofPrintf PracticeSizeof Practice
3. Operators
Assignment, Comparison, Not Equal ToSum, Difference, Increment, DecrementMultiplication, Division and ModuloComparison OperatorsComparison Operators PracticeLogical OperatorsLogical Operators Practice
4. Control Statements
If-else Operatorif-else Operator PracticeTernary OperatorSwitch, BreakWhile, Do-WhileFor, ContinueFor Loop Practice
5. Functions
Structure of the FunctionDeclaration, Type and ReturnArgumentsPassing ArgumentsHeader, Prototypes Void, Recursion
6. Pointers
Pointers are around UsReferences and DereferencesPointersMalloc and FreeFunctions, Arrays and Two PointersVoid

book
Header, Prototypes

Throughout this course, we've consistently utilized the stdio.h file. This file serves as the standard input/output header.

Contained within it is the prototype for the printf() function, a function we've employed in every lesson.

Here's an intentional error to illustrate a point:

c

Main

copy

              
12345678

            
//#include <stdio.h>

int main()
{
    printf("Using `printf()` without `stdio.h`");

    return 0;
}

Should you exclude the stdio.h file, the printf() function will cease to function. Invoking this function without the header will yield an error.

Understanding Header Files

Header files like stdio.h house declarations of variables, arrays, and function prototypes. They modularize your project code, allowing you to attach components as necessary. This approach streamlines your projects.

Function Prototypes

A function prototype is essentially a function declaration without its actual implementation. Think of a prototype as a "heads-up" to the compiler, signaling the existence of your function.

python

It resembles a standard function but without the details. Take note of the concluding semicolon (;). Now, how do we handle a function prototype in a dedicated header file?

Multi-File Projects

Up to this point, we've written our variables and functions in a single file, right alongside the main function. However, in professional development, this isn't the norm. Let's devise a function to estimate the charge/discharge duration of a capacitor based on its capacitance and resistance.

Our project will be segmented into three files:

  1. func.h - this will store the function prototype;

  2. func.c - the implementation of our capacitor charge/discharge time calculation function will reside here;

  3. main.c - this primary file will be where all functions are invoked.

python
python
python

Executing this program yields:

python

Note

%.2f specifies that the result should be displayed with two decimal places.

question mark

So, what exactly is a function prototype?

Select the correct answer

Everything was clear?

How can we improve it?

Thanks for your feedback!

SectionΒ 5. ChapterΒ 5

Ask AI

expand
ChatGPT

Ask anything or try one of the suggested questions to begin our chat

course content

Course Content

C Basics

C Basics

1. Introduction
Structure of the C-ProgramEssentials of C ProgramHow to Run the Program?
2. Data
DataVariablesPrintfIntroduction to ArraysTwo Dimensional ArraysChar and StringSizeofPrintf PracticeSizeof Practice
3. Operators
Assignment, Comparison, Not Equal ToSum, Difference, Increment, DecrementMultiplication, Division and ModuloComparison OperatorsComparison Operators PracticeLogical OperatorsLogical Operators Practice
4. Control Statements
If-else Operatorif-else Operator PracticeTernary OperatorSwitch, BreakWhile, Do-WhileFor, ContinueFor Loop Practice
5. Functions
Structure of the FunctionDeclaration, Type and ReturnArgumentsPassing ArgumentsHeader, Prototypes Void, Recursion
6. Pointers
Pointers are around UsReferences and DereferencesPointersMalloc and FreeFunctions, Arrays and Two PointersVoid

book
Header, Prototypes

Throughout this course, we've consistently utilized the stdio.h file. This file serves as the standard input/output header.

Contained within it is the prototype for the printf() function, a function we've employed in every lesson.

Here's an intentional error to illustrate a point:

c

Main

copy

              
12345678

            
//#include <stdio.h>

int main()
{
    printf("Using `printf()` without `stdio.h`");

    return 0;
}

Should you exclude the stdio.h file, the printf() function will cease to function. Invoking this function without the header will yield an error.

Understanding Header Files

Header files like stdio.h house declarations of variables, arrays, and function prototypes. They modularize your project code, allowing you to attach components as necessary. This approach streamlines your projects.

Function Prototypes

A function prototype is essentially a function declaration without its actual implementation. Think of a prototype as a "heads-up" to the compiler, signaling the existence of your function.

python

It resembles a standard function but without the details. Take note of the concluding semicolon (;). Now, how do we handle a function prototype in a dedicated header file?

Multi-File Projects

Up to this point, we've written our variables and functions in a single file, right alongside the main function. However, in professional development, this isn't the norm. Let's devise a function to estimate the charge/discharge duration of a capacitor based on its capacitance and resistance.

Our project will be segmented into three files:

  1. func.h - this will store the function prototype;

  2. func.c - the implementation of our capacitor charge/discharge time calculation function will reside here;

  3. main.c - this primary file will be where all functions are invoked.

python
python
python

Executing this program yields:

python

Note

%.2f specifies that the result should be displayed with two decimal places.

question mark

So, what exactly is a function prototype?

Select the correct answer

Everything was clear?

How can we improve it?

Thanks for your feedback!

SectionΒ 5. ChapterΒ 5
We're sorry to hear that something went wrong. What happened?
some-alt