What are 'macros' and 'constants' used for in C?

Asked by Last Modified  

2 Answers

Learn C Language

Follow 2
Answer

Please enter your answer

Savitra

+46-768394959 (Whatsapp number) please reach me on this number

Macros: Macros are defined using the #define preprocessor directive. They are not variables; instead, they are symbolic constants. Macros are replaced by their values at compile-time through a process called macro expansion. Macros can include code and perform text substitution. They are processed...
read more
Macros: Macros are defined using the #define preprocessor directive. They are not variables; instead, they are symbolic constants. Macros are replaced by their values at compile-time through a process called macro expansion. Macros can include code and perform text substitution. They are processed by the preprocessor before the actual compilation of the code. Macros can be used to create reusable code snippets, conditional compilation, or to define constants with complex expressions. Constants: Constants are variables that are declared as read-only, and their values cannot be changed during the program's execution. In C, you can define constants using the const keyword. These are typically used for values that should not change throughout the program. Constants are stored in memory, and their values are accessed like regular variables. read less
Comments
Dislike Bookmark

Experienced Computer trainer having worked in IT sector for 20 years.

The const keyword causes the identifier size to be allocated in the read-only memory. This means that the value of the identifier can not be changed by the executing program. MACROS are efficient than the const statements as they are not given any memory, being more Readable and Faster in execution!
Comments
Dislike Bookmark

Related Questions

In C/C++, when should you use the comma (,) operator instead of the semicolon (;) statement terminator?
int a=2; b=a; b=a+2; Instead of the above two statements we can write it as b=(a,a+2); The value of b is 4
Thimma
0 0
View Comments5
What are pointers in C language?
Hi Imran, Hope you are doing good. Are you looking for short answer or long answer? :) Pointers in C are variables that store memory addresses. They point to the location of another variable, allowing...
Imran
0 0
View Comments7
Basics of 'C'language
C is middle level language, using C you can write program which directly interact with the hardware like device driver programming or you can write GUI application. C is very powerful language compare...
Raghavendra
Why are operating systems written in C? Why aren't other languages used?
low-level access to hardware, performance, and historical reasons.
Chandramami
0 0
View Comments5
What are the __DATE__ and __TIME__ preprocessor commands?
Preprocessor is first statement that get executed. It tells compiler to pre-process before compilation. _DATE --> The current date as a character literal in "MMM DD YYYY" format. and The current time...
Subhasish

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

Ask a Question

Related Lessons

What is Safety-Critical Software?
A software whose failure may cause death or injuries to the users called Safety-Critical Software.The software present as part of Aeroplanes, or present in Rail as railway signalling software or Automotive...

Vihanga Embedsoft

0 0
View Comments0
C INTRODUCTION

Nagaraju Tanguturi

0 0
View Comments0
Can we store different data types in a stack?
Yesterday, one of my Facebook friend asked me this question. My answer is "yes", and in this post I will discuss how could we do this.I am a great supporter of working with unions and I will be using union...

Shiladitya Munshi

0 0
View Comments0
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
View Comments0
C Program Sample Application
//Standard Library Functions(Header Files used) #include<stdio.h> #include <conio.h> //Main method int main() { // function for clearing screen clrscr(); // function to print the output...

Salim Ahmed Ansari

0 0
View Comments0

Recommended Articles

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 >

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 >

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 >

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 Noida
C Language Classes in Ghaziabad
C Language Classes in Gurgaon

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