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

Visualization, Visualization Visualization is a general method in contr...

Visualization Visualization is a general method in contract to search based tools.  In this method visual aids are given like pictures to assist the programmer in evaluating th

Illustrate the logical view of a system, Illustrate the Logical view of a s...

Illustrate the Logical view of a system The Logical view of a system serves to describe existence and meaning of key abstractions and mechanism which form problem space, or wh

How the simulation is done, How the simulation is done Data is entered ...

How the simulation is done Data is entered into the computer and simulation is run. The below scenarios may be tried out: -  Timing of lights varied to see how traffic flow

Explain variable-partition contiguous storage allocation, Explain the conce...

Explain the concept of variable-partition contiguous storage allocation. Suppose that we have 1024K main memory available in that 128K is occupied through operating system pro

Time complexity in the worst case, Speicified the following piece of code: ...

Speicified the following piece of code: int i = 1; int j = 4; while (i     {      if (i%3 == 0) i+=3;      else i+=4;        if (j%2 == 0) j*=4;      els

Slower layer to a faster layer, Given a four level hierarchical storage sys...

Given a four level hierarchical storage system consisting of: cache,  primary storage, secondary storage, and tertiary storage. Suppose the following:  programs may be executed on

What is .net and .net framework, What is .NET / .NET Framework?  It is ...

What is .NET / .NET Framework?  It is a Framework in which Windows applications might be developed and run. The Microsoft .NET Framework is a platform for building, deploying,

Explain the resolution of an ADC, Explain the Resolution of an ADC. ...

Explain the Resolution of an ADC. Ans. Resolution- It  is  the  smallest  possible  change  in  input  voltage  the same as  the  fraction  of percentage of the full s

Biological motivation - two layer artificial neural networks, Biological Mo...

Biological Motivation : However remember there that in discussion first lecture is about how people have answered the question like: "How are we going to get an agent to proce

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