- World's Largest Collection of Interview Questions & Answers, FAQs, queries, sample papers, exam papers, dumps, what, why, how, where, when questions
Interview Success Kit - Get Success in Job Interviews Interview Success Kit - 30,000 Interview Que. & Ans.
Covers 30,000+ Interview Questions asked in actual MNC Interviews - all with model answers.
Get Your Dream Job Now -
Sponsored Links
Interview Questions
Our Services

Question :
Advantages and disadvantages of using macro and inline functions?
Category Embedded Systems Interview Questions
Rating (3.5) By 38 users
Added on 1/21/2011
Views 2506
Rate it!

Advantage: Macros and Inline functions are efficient than calling a normal function. The times spend in calling the function is saved in case of macros and inline functions as these are included directly into the code.

Disadvantage: Macros and inline functions increased the size of executable code.

Submitted by Naveen Rao (


Difference in inline functions and macro
1) Macro is expanded by preprocessor and inline function are expanded by compiler.
2) Expressions passed as arguments to inline functions are evaluated only once while _expression passed as argument to inline functions are evaluated more than once.

More over inline functions are used to overcome the overhead of function calls. Macros are used to maintain the readbility and easy maintainence of the code.

Submitted by Pooja Agrawal (

Inline Functions versus Macros

Although inline functions are similar to macros (because the function code is expanded at the point of the call at compile time), inline functions are parsed by the compiler, whereas macros are expanded by the preprocessor. As a result, there are several important differences:


Inline functions follow all the protocols of type safety enforced on normal functions.

Inline functions are specified using the same syntax as any other function except that they include the inline keyword in the function declaration.

Expressions passed as arguments to inline functions are evaluated once. In some cases, expressions passed as arguments to macros can be evaluated more than once.

Posted by: juke1909

Contact juke1909 Contact juke1909

these get expanded during preprossing whenver invoked by the code.
1. calling macro too many times in the code will increase the size of the code.
2. simple operation can be performed which does not increase the size of the code.
3. Few operations are unpredictable.
#define SQA(x) (++x * ++x)

int main()
int a = 2;
processed during compilation.
compiler optimizes a inline function either as a function if the performance overhead in calling a function is less compared to macro implementation, OR, it is implemented as Macro itself.
This optimization makes inline more preferable than macro

if function called:
a. return address had to be moved to stack.
b. register content has to be moved to stack.
c. function arguments has to be moved to stack.
d. memory allocation for the new function execution in ram has to done.
e. program counter has to loaded with the new address.

Posted by: Murali Prasath

Contact Murali Prasath Contact Murali Prasath

Another difference is Inline functions check for the type of parameter passed, Macros don't check parameter type, you can pass strings to a macro that does some integer arithmetic.
little correction in pooja answer in point 2.
2) Expressions passed as arguments to inline functions are evaluated only once while _expression passed as argument to inline functions are evaluated more than once.
Expression passed to inline functions are evaluated and result is passed as value, whereas expressions passed as argument to macros are expanded, and if passed

#define MAX(a, b) ((a < b) ? b : a)

int main( void)


cout << "Maximum of 10 and 20 is " << MAX("20", "10") << endl;

return 0;


Posted by: Mujeeb

Contact Mujeeb Contact Mujeeb

In MACROS the code is literally copied into the location it was called from. So if the user passes a "double" instead of an "int" then problems could occur.

In INLINE functions, if this senerio happens the compiler will complain about incompatible types.

In MACRO --> you cannot make the macro return something which is not the result of the last expression invoked inside it.

In INLINE --> you can return any value by using keyword return();

In MACROS -- > debugging is tough (because they refer to the expanded code, rather than the code the programmer typed.)
INLINe --> debugging is easy

Posted by: calvin

Contact calvin Contact calvin

If you have the better answer, then send it to us. We will display your answer after the approval.
Rules to Post Answers in

  • There should not be any Spelling Mistakes.
  • There should not be any Gramatical Errors.
  • Answers must not contain any bad words.
  • Answers should not be the repeat of same answer, already approved.
  • Answer should be complete in itself.
  • Name :*
    Email Id :*
    Answer :*
    Verification Code Code Image - Please contact webmaster if you have problems seeing this image code Not readable? Load New Code
    Process Verification Enter the above shown code: *
    Inform me about updated answers to this question

    Related Questions
    View Answer
    Why cannot arrays be passed by values to functions?
    View Answer
    Can structures be passed to the functions by value?
    View Answer

    Please Note: We keep on updating better answers to this site. In case you are looking for Jobs, Pls Click Here - Best Freshers & Experienced Jobs Website.

    View ALL Embedded Systems Interview Questions & Answers

    User Options
    Latest 20 Questions
    Where are Blocks located?
    How to make a block cacheable?
    What is the need of making Blocks cacheable?
    Explain groups concept in user management of Concrete5?
    What is department?
    What is departmental accounting?
    What is departmental accounting?
    What is departmental accounting?
    What is meant by invoice price?
    What are the features of dependent branch?
    What is a foreign branch?
    What is a foreign branch?
    What is a foreign branch?
    Name and explain the two types of Inland Branch.
    Explain Inland Branch.
    What are the types of branch?
    What is the responsibility of a branch manager?
    Who is a branch manager?
    What is the primary objective of branch accounting?
    What is branch accounting?

    Fresher Jobs | Experienced Jobs | Government Jobs | Walkin Jobs | Company Profiles | Interview Questions | Placement Papers | Companies In India | Consultants In India | Colleges In India | Exams In India | Latest Results | Notifications In India | Call Centers In India | Training Institutes In India | Job Communities In India | Courses In India | Jobs by Keyskills | Jobs by Functional Areas

    Testing Articles | Testing Books | Testing Certifications | Testing FAQs | Testing Downloads | Testing Interview Questions | Testing Jobs | Testing Training Institutes

    Gate Articles | Gate Books | Gate Colleges | Gate Downloads | Gate Faqs | Gate Jobs | Gate News | Gate Sample Papers | Gate Training Institutes

    MBA Articles | MBA Books | MBA Case Studies | MBA Business Schools | MBA Current Affairs | MBA Downloads | MBA Events | MBA Notifications | MBA FAQs | MBA Jobs
    MBA Job Consultants | MBA News | MBA Results | MBA Courses | MBA Sample Papers | MBA Interview Questions | MBA Training Institutes

    GRE Articles | GRE Books | GRE Colleges | GRE Downloads | GRE Events | GRE FAQs | GRE News | GRE Training Institutes | GRE Sample Papers

    IAS Articles | IAS Books | IAS Current Affairs | IAS Downloads | IAS Events | IAS FAQs | IAS News | IAS Notifications | IAS UPSC Jobs | IAS Previous Question Papers
    IAS Results | IAS Sample Papers | IAS Interview Questions | IAS Training Institutes | IAS Toppers Interview

    SAP Articles | SAP Books | SAP Certifications | SAP Companies | SAP Study Materials | SAP Events | SAP FAQs | SAP Jobs | SAP Job Consultants
    SAP Links | SAP News | SAP Sample Papers | SAP Interview Questions | SAP Training Institutes |

    Copyright ©2003-2016, All Rights Reserved.
    Privacy Policy | Terms and Conditions

    Cache = 0.015625 Seconds