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

State the important features of operating system, a. Define operating syste...

a. Define operating system? State the important features of operating system? b. Describe the following facilities for implementing interacting processes in programming language

Visual basic application, Name the platforms by which visual basic applicat...

Name the platforms by which visual basic applications are available? Ans) Most of the visual basic applications are available on 32 bit Intel platforms. These applications also

Number square, Ask question #MinimYour professor wants you to fill a two-di...

Ask question #MinimYour professor wants you to fill a two-dimensional N by N matrix with some numbers by following a specific pattern. According to his explanation as in the figure

Drawbacks of specifying parameter assignments using defparam, The disadvant...

The disadvantages of specifying parameter assignments using defparam are: -  Parameter  is  essentially specified  by  the  scope  of  hierarchies  underneath  which  it exists

What is library, What is library? A library is a collection of classes ...

What is library? A library is a collection of classes that are useful in most of the contexts. Classes must have accurate and thorough explanations to help users.

Give an example of first fit and best fit algorithms, Given memory partiti...

Given memory partitions of 100k, 500k, 200k, 300k, and 600k (in order), apply first fit and best fit algorithms to place processes with the space requirement of 212k, 417k, 112k an

The number of control lines for a 8 – to – 1 multiplexer, What is the numbe...

What is the number of control lines for a 8 - to - 1 multiplexer ? Ans. There are 3 control lines, for an 8 to 1 Multiplexer. The control signals are utilized to steer any one

Explain the working of hundred-line exchange, In a hundred-line exchange 24...

In a hundred-line exchange 24 two-motion selectors are used. Draw the schematic you suggest for this exchange and explain its working. How many simultaneous calls can be made durin

What is parallel loop construct, Q. What is Parallel Loop Construct? Pa...

Q. What is Parallel Loop Construct? Parallel loop construct is a shortcut for specifying parallel construct comprising one loop construct and no other statements. The syntax of

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