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 about of unicode, Q. Explain about of Unicode? This is a newer ...

Q. Explain about of Unicode? This is a newer International standard for character representation. Unicode offers a unique code for each character irrespective of Program, platf

Approaches for development of information systems, Q. Approaches for develo...

Q. Approaches for development of information systems? Numerous approaches are available for development of Information Systems. They are as below: • Model Driven: It put e

When gravity is the merely force acting on an object, Q. When gravity is th...

Q. When gravity is the merely force acting on an object the object is in what? Answer:- One respond is that it is in free-fall in a vacuum to eliminate atmospheric drag.

Give the syntax switch statement, Give the syntax  switch statements C...

Give the syntax  switch statements Consider the following example. This is a function which converts an integer into a vague description. It is useful where we are only concer

#chemistry, Please explain the construction and working of calomel electrod...

Please explain the construction and working of calomel electrode..

State the approaches to organizing stored program control, Determine the ap...

Determine the approaches to organizing stored program control There are 2 approaches to organizing stored program control: 1.  Centralized: In this control, all control equi

Explain list directive in assembly language, Q. Explain list directive in a...

Q. Explain list directive in assembly language? A list directive causes assembler to generate an annotated listing on printer, video screen, disk drive or any combination of th

Liquid crystal displays, LCDs are the screens of choice for lightweight scr...

LCDs are the screens of choice for lightweight screens andportable computers. They consume very little electricity and have advanced technically to quite good resolutions and colou

Simplify the expressions using boolean postulates, Simplify the given expre...

Simplify the given expressions using Boolean postulates XY + X‾Z‾  + XY‾Z (XY + Z) Ans. XY + X‾Z‾ + XY‾Z (XY + Z) = XY + X‾Z‾ + XY‾Z (XY + Z) = XY + X‾Z‾  + XXYY‾Z

Define about classes of object oriented modelling, Define about classes of ...

Define about classes of object oriented modelling A class is a collection of things, or concepts that have the same properties. Each of these concepts or things is known an obj

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