UrbanPro
Login Ask & Answer Success Stories Paid Courses Free Classes Tuition & Classes Fees Write a Review All Categories Help Center
Post your Learning Need Signup as a Tutor
✕

Popular Cities

Bangalore

Hyderabad

Delhi

Mumbai

Chennai

Pune

Kolkata

Gurgaon

Ahmedabad

Jaipur

Noida

✕

Learn C Language from the Best Tutors

  • Affordable fees
  • 1-1 or Group class
  • Flexible Timings
  • Verified Tutors

Book a Free Demo

C Language > Learn C Language > How can you avoid including a header more than once?
✕

Search in

How can you avoid including a header more than once?

Asked by Last Modified  

7 Answers

Learn C Language

Follow 0
Answer

Please enter your answer

Most common ways, use: #pragma once on top of the each header file (though non standard but most compilers support it) or do the following, if you want to protect abc.h from multiple inclusions then in abc.h write following lines: #ifndef _ABC_H_ #define _ABC_H_ ....Contents of your file... #e...
Comments
Dislike Bookmark

To avoid multiple inclusions of the same header file we use the #ifndef, #define and #endif preprocessor directives.
Comments
Dislike Bookmark

Software Professional Trainer with 26+ years of Experience in Software Design and Development

You can use macro ifndef for example #ifndef TEST_H #define TEST_H ..... other statements here ..... other statements here ..... other statements here #endef
Comments
Dislike Bookmark

Trainer

You can use the conditional preprocessor directive named #ifndef to check whether that symbolic name has already been assigned. If it is assigned, you should not include the header, because it has already been preprocessed. If it is not defined, you should define it to avoid any further inclusions of...
read more
You can use the conditional preprocessor directive named #ifndef to check whether that symbolic name has already been assigned. If it is assigned, you should not include the header, because it has already been preprocessed. If it is not defined, you should define it to avoid any further inclusions of the header. read less
Comments
Dislike Bookmark

Tutor

Use following in your header file. #ifndef "header_name" #define "header_name" /*header definition starts here*/ #endif /* header file ends here*/ Whenever you will include the same header file, above line wont allow it to get added again. first line of above code checks for header file ,if...
read more
Use following in your header file. #ifndef "header_name" #define "header_name" /*header definition starts here*/ #endif /* header file ends here*/ Whenever you will include the same header file, above line wont allow it to get added again. first line of above code checks for header file ,if not defined, then the second line starts its definition and 3rd line end the definition. read less
Comments
Dislike Bookmark

Programming Trainer

Just write the entire program in only file and include headers once only.
Comments
Dislike Bookmark

Thank You for the question Deepak....... You can use conditional pre-processor directive #ifdef or #ifndef. Thank You, Team DishaaPro www.dishaapro.com
Comments
Dislike Bookmark

View 5 more Answers

Related Questions

What is the actual size of INT in the C language, 2 or 4 bytes?
The actual size to int is determined by the compiler as the program runs. But theoretically the size is 2 bytes. You can increase the size by adding keyword long infront of it to make the size 4 bytes. Eg int a; // 2 bytes Long int b; // 4 bytes
Kunal
Do array subscripts always start with zero?
It purely depends on the programming language. C, C#, Java all provide array indices starting from zero (0). COBOL, FORTRAN, ALGOL etc. languages provide array indices starting from 1.
Avishkar
How do I start learning C programming and finish it in one month?
Use a book named "Let us C"by yashwant t kanetkar. Or simply by taking a class from teachers on urbanpro
Pallavi
0 0
8
What is the difference between a string and an array?
String is array of characters terminated with null.
Rakes
What will the pre-processor do for a program?
The pre processor takes a look at your source code just before it goes off to the compiler, does a little formatting, and carries out any instructions you have given it. Each # command that the preprocessor...
Neel
0 0
6

Now ask question in any of the 1000+ Categories, and get Answers from Tutors and Trainers on UrbanPro.com

Ask a Question

Related Lessons

Necessity of Theory and Practical in Computer Science.
Upon studying a subject both theory and practical are important. Usually many schools concentrate more on theory and the marks not on the practical. Other and opposite kind of people prefer practical...

Ganesa M.

0 0
0
Datatypes in C Language
Data types in C Language Data types specify how we enter data into our programs and what type of data we enter. C language has some predefined set of data types to handle various kinds of data that...

Venkateswararao S.

0 0
0
Bit wise operators in C
Bit Wise Operators Bit Wise operators are manipulates of individual bits with in a word of memory. The bit wise operators can be divided in to three general category. One’s Complement...

Venkateswararao S.

0 0
0
C INTRODUCTION

Nagaraju Tanguturi

0 0
0
C Program-Infinite Loop[For] Demo
//Header Files #include<stdio.h>#include<conio.h> //Main function void main(){ //Function for clearing screen clrscr(); //Infinite for loop for(;;) { printf("Hello!"); } //Function for...

Salim Ahmed Ansari

0 0
0

Recommended Articles

Lasya Infotech: An educational Training...

Lasya Infotech is a Hyderabad based IT training institute founded in 2016 by O Venkat. Believing in his innovation, passion and persistence and with a diverse blend of experience, he started his brainchild to deliver exemplary professional courses to aspiring candidates by honing their skills. Ever since the institute envisions...

Read full article >

Brilliant Academy, a reputed B. Tech Tuition...

Brilliant Academy is one of the reputed institutes for B.Tech tuition classes. This institute is specialised in delivering quality tuition classes for B.E, Engineering - all streams and Engineering diploma courses. Incorporated in 2012, Brillant Academy is a brainchild of Mr Jagadeesh. The main motto of the academy is to...

Read full article >

Learn Hadoop and Big Data

Hadoop is a framework which has been developed for organizing and analysing big chunks of data for a business. Suppose you have a file larger than your system’s storage capacity and you can’t store it. Hadoop helps in storing bigger files than what could be stored on one particular server. You can therefore store very,...

Read full article >

Make a Career as a BPO Professional

Business Process outsourcing (BPO) services can be considered as a kind of outsourcing which involves subletting of specific functions associated with any business to a third party service provider. BPO is usually administered as a cost-saving procedure for functions which an organization needs but does not rely upon to...

Read full article >

Find C Language Classes near you
C Language Classes in Bangalore
C Language Classes in Hyderabad
C Language Classes in Delhi
C Language Classes in Pune
C Language Classes in Chennai
C Language Classes in Mumbai
C Language Classes in Kolkata
C Language Classes in Gurgaon
C Language Classes in Noida
C Language Classes in Ghaziabad

Looking for C Language Classes?

Learn from the Best Tutors on UrbanPro

Are you a Tutor or Training Institute?

Join UrbanPro Today to find students near you
X

Looking for C Language Classes?

The best tutors for C Language Classes are on UrbanPro

  • Select the best Tutor
  • Book & Attend a Free Demo
  • Pay and start Learning

Learn C Language with the Best Tutors

The best Tutors for C Language Classes are on UrbanPro

This website uses cookies

We use cookies to improve user experience. Choose what cookies you allow us to use. You can read more about our Cookie Policy in our Privacy Policy

Accept All
Decline All

UrbanPro.com is India's largest network of most trusted tutors and institutes. Over 55 lakh students rely on UrbanPro.com, to fulfill their learning requirements across 1,000+ categories. Using UrbanPro.com, parents, and students can compare multiple Tutors and Institutes and choose the one that best suits their requirements. More than 7.5 lakh verified Tutors and Institutes are helping millions of students every day and growing their tutoring business on UrbanPro.com. Whether you are looking for a tutor to learn mathematics, a German language trainer to brush up your German language skills or an institute to upgrade your IT skills, we have got the best selection of Tutors and Training Institutes for you. Read more

ThinkVidya Learning Pvt Ltd © 2010-2025 All Rights Reserved