Defines a macro, Computer Engineering

Assignment Help:

Defines a macro

Defines a macro with the given name, having as its value the given replacement text. After that (for the rest of the current source file), wherever the preprocessor sees that name, it will replace it with the replacement text. The name follows the same rules as ordinary identifiers (it can contain only letters, digits, and underscores, and may not begin with a digit). Since macros behave quite differently from normal variables (or functions), it is customary to give them names which are all capital letters (or at least which begin with a capital letter). The replacement text can be absolutely anything--it's not restricted to numbers, or simple strings, or anything.

The most common use for macros is to propagate various constants around and to make them more self-documenting. We've been saying things like

char line[100];

...

getline(line, 100);

but this is neither readable nor reliable; it's not necessarily obvious what all those 100's scattered around the program are, and if we ever decide that 100 is too small for the size of the array to hold lines, we'll have to remember to change the number in two (or more) places.

A much better solution is to use a macro:

#define MAXLINE 100 char line[MAXLINE];

...

getline(line, MAXLINE);

 


Related Discussions:- Defines a macro

Explain the main part of step by step switching system, Explain the main pa...

Explain the main part of configuration of a step by step switching system with the help of a neat diagram . Configuration of a step by step switching system: A step

What are semaphores, What are semaphores? Semaphore : A semaphore is a...

What are semaphores? Semaphore : A semaphore is a synchronization tool which gives a general-purpose solution to controlling access to critical sections. It s an abstract data

How two domain servers having same set of names, Does it makes sense for tw...

Does it makes sense for two domain servers to contain exactly the same set of names? Why or why not? Yes. This is very advantageous for 2-domain servers having same set of name

Explain about dual in line memory modules, Q. Explain about Dual In line Me...

Q. Explain about Dual In line Memory Modules? A DIMM is capable of delivering 64 data bits right away. Usual DIMM capacities are 64MB and up. Every DIMM has 84 gold patted conn

Give difference between assembler and interpreter, Give difference between ...

Give difference between assembler and interpreter. Assembler: It is the translator for an assembly language of computer. An assembly language is a low-level programming langu

How 74147 series ttl can be used as a decimal-to-bcd encoder, Illustrate ho...

Illustrate how 74147 series TTL can be used as a decimal-to-BCD encoder. Ans. Available IC in 74 series is 74147 that is a priority encoder. Such IC has active low inp

Determine how simulation can be developed, Determine how Simulation can be ...

Determine how Simulation can be developed To determine how a simulation can be developed for use in a real situation the below illustration has been chosen. Scenario chosen is

Ms access database through menu driven selections, Would you like to easily...

Would you like to easily automate your MS Access database through menu driven selections? This can be accomplished by producing a form with customized buttons that point to macr

How video effects alters a video, Question : (a) What are the main aspe...

Question : (a) What are the main aspects that should be considered when dealing with green screen? (b) Explain clearly how these video effects alters a video using an illust

Instruction per cycle in RISC, Q. Instruction per cycle in RISC? One in...

Q. Instruction per cycle in RISC? One instruction per cycle: A machine cycle is total time taken to fetch two operands from registers perform ALU operation on them and store re

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd