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

What are the components of loadrunner, The workings of LoadRunner are The V...

The workings of LoadRunner are The Virtual User Generator, Controller, and the Agent process, LoadRunner examines and Monitoring, LoadRunner Books Online. What Component of LoadRun

What is meant by latch, Latch is a D- type flip-flop used as a temporary st...

Latch is a D- type flip-flop used as a temporary storage device controlled by a timing signal, which can kept 0 or 1. The primary function of a Latch is data storage. It is used in

Example of calculate maximum access time & cost of switch, Calculate the ma...

Calculate the maximum access time that can be permitted for the data and control memories in a TSI switch with a single input and single output trunk multiplexing 2500 channels. Al

Io devices and i/o subsystem and direct memory access, Why IO devices canno...

Why IO devices cannot be connected directly to the system bus? Ans: The IO devices can't be directly connected to the system bus because the following reason A) The data tra

What is the need of interrupt controller, What is the need of interrupt con...

What is the need of interrupt controller?  The interrupt controller is employed to expand the interrupt inputs. It can handle the interrupt requests from several devices and pe

Working of compact disk - computer architecture, Working of compact disk: ...

Working of compact disk: A CD is built from 1.2 mm thick, approximately all-pure polycarbonate plastic and its weighs is approximately 15-20 grams. From the core outward compo

4 bit comparator, how to breadboARD THE 4 BIT COMPARATOR

how to breadboARD THE 4 BIT COMPARATOR

How can we read .doc document in asp.net, How can I read .doc document in A...

How can I read .doc document in ASP.Net? You can read from a text file like this.   Private void Button12_Click(object sender, System.EventArgs e) { string path="C:

Mathematical applications, The current 32 and 64 bit machines can represent...

The current 32 and 64 bit machines can represent integers of around 9 digits and 30 digits respectively, while various scientific and mathematical applications have to represent in

Illustrate about fourth generation computers, Q. Illustrate about fourth ge...

Q. Illustrate about fourth generation computers? One of the main milestones in IC technology is Very large scale integration (VLSI) where thousands of transistors can be integr

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