How can you check to see whether a symbol is defined?

Asked by Last Modified  

20 Answers

Learn C Language

Follow 1
Answer

Please enter your answer

Chetan Santha

Professional Tutor with 15 years of experience.

You can use the #ifdef and #ifndef preprocessor directives to check whether a symbol has been defined (#ifdef) or whether it has not been defined (#ifndef).
Comments
Dislike Bookmark

Thank You for the question .... To check the symbol has been defined use the #ifdef function. Thank You, Team DishaaPro www.dishaapro.com
Comments
Dislike Bookmark

Having 17 years of teaching experience

To check whether the symbol is defined or not you have to use #ifdef or #ifndef. You can check like a simple if condition: #ifdef NAME (the course of ation i.e. your c / c++ code) #else (the course of ation i.e. your c / c++ code) #endif
Comments
Dislike Bookmark

You can use the #ifdef and #ifndef preprocessor directives to check whether a symbol has been defined (#ifdef) or whether it has not been defined (#ifndef).
Comments
Dislike Bookmark

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

#ifdef and #ifndef preprocessor directives to check whether a symbol has been defined (#ifdef) or (#ifndef). #ifndef OS #define OS unix #endif ========= #ifdef UNIX #define OS unix #else #define OS windows #endif
Comments
Dislike Bookmark

Tutor

you can use #if def and #ifndef
Comments
Dislike Bookmark

Trainer

You can use the #ifdef and #ifndef preprocessor directives to check whether a symbol has been defined (#ifdef) or whether it has not been defined (#ifndef).
Comments
Dislike Bookmark

You can use the #ifdef and #ifndef preprocessor directives to check whether a symbol has been defined.
Comments
Dislike Bookmark

defined where in what scope? And where do you want to check in the source code or object file or library or executable?
Comments
Dislike Bookmark

Mathematics and Computer science guide

You can use the #ifdef and #ifndef preprocessor directives to check whether a symbol has been defined (#ifdef) or whether it has not been defined (#ifndef). Many programmers like to ensure that their own version of NULL is defined, not someone else's. This task can be accomplished as shown here: #ifdef...
read more
You can use the #ifdef and #ifndef preprocessor directives to check whether a symbol has been defined (#ifdef) or whether it has not been defined (#ifndef). Many programmers like to ensure that their own version of NULL is defined, not someone else's. This task can be accomplished as shown here: #ifdef NULL #undef NULL #endif #define NULL (void*) 0 The first line, #ifdef NULL, checks to see whether the NULL symbol has been defined. If so, it is undefined using #undef NULL and the new definition of NULL is defined. To check whether a symbol has not been defined yet, you would use the #ifndef preprocessor directive. read less
Comments
Dislike Bookmark

View 18 more Answers

Related Questions

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
Why is the C program giving the wrong output?
Hai, maybe the syntax in the program was wrong, once check it and try again.
Chandra
0 0
5
What purpose does \n have in C programming?
is used for new line. It prints the output in New or next line
Nasar
0 0
9
Can we have if inside else-if or else in C programming language?
Yes it is possible to do so. The if... else if..... else statements support one other inside themselves... so...
Kirthi
How and where do I start learning C programming?
To start learning C programming, you can follow a structured approach that includes both theoretical knowledge and practical implementation. Begin with understanding the basics of C, including variables,...
Gaurav
0 0
7

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

Ask a Question

Related Lessons

Programing Languages Learning Tricks
You want to learn that new language or library or framework as soon as possible, right? That’s understandable. Fortunately, there are a handful of tips that can help you to better retain all of that...
H

Harshal G.

0 0
0
C INTRODUCTION

Nagaraju Tanguturi

0 0
0
Tips of learning Java Language/Other Programming Languages
1.You should know the basic concept: If we talk about programming languages so basic concept are same in all the high level languages. So you should know the basic concept firstly then you can easily understand...
I

Icreative Solution

0 0
0
Tress And Its Traversal
Depth First Traversals:(a) Inorder (Left, Root, Right) : 4 2 5 1 3(b) Preorder (Root, Left, Right) : 1 2 4 5 3(c) Postorder (Left, Right, Root) : 4 5 2 3 1 Trees are one of the data structures like...

Sunil Yadav

1 0
0
Be prepared to get trained--init
Before starting the training,students must be mentally prepared for acceptance of new knowledge. Students must attend training with open minded forgetting the position they are working.This will help...
S

Smartnub Softsolutions

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 >

Why Should you Become an IT Consultant

Information technology consultancy or Information technology consulting is a specialized field in which one can set their focus on providing advisory services to business firms on finding ways to use innovations in information technology to further their business and meet the objectives of the business. Not only does...

Read full article >

What is Applications Engineering all about?

Applications engineering is a hot trend in the current IT market.  An applications engineer is responsible for designing and application of technology products relating to various aspects of computing. To accomplish this, he/she has to work collaboratively with the company’s manufacturing, marketing, sales, and customer...

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 Noida
C Language Classes in Gurgaon
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