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 disadvantages of eprom, What are disadvantages of EPROM? The c...

What are disadvantages of EPROM? The chip must be physically removed from the circuit for reprogramming and its whole contents are erased by the UV light.

stores on each line a part number, Make a file "parts_inv.dat" that stores...

Make a file "parts_inv.dat" that stores on each line a part number, cost, and quantity in inventory, e.g.: 123 5.99 52 456 3.97 100 333 2.22 567 Use fscanf to read this infor

Customer credit-rating software , Gordon Grant, majority shareholder and Ch...

Gordon Grant, majority shareholder and Chief Executive Officer of Finance-IT Ltd, is determined to be one of the entrepreneurs making money out of the recession. He started the fir

Explain one two motion selector per subscriber, What is 1 00 line exchang...

What is 1 00 line exchange with one two-motion selector per subscriber. Design: In, Strowger switching system is designed by using one two-motion selector for all subscrib

Value - elements of composition, Value Value is the relative amount of ...

Value Value is the relative amount of light and darkness in an image or a particular colour within an image. Value is also known as Tone and refers to the way the artist has re

The alignment of a type ''c'' field in a report, The alignment of a type 'c...

The alignment of a type 'c' field in a report is? ? Left Aligned.

What is the main function of the memory-management unit, What is the main f...

What is the main function of the memory-management unit? The runtime mapping from virtual to physical addresses is done by a hardware device known as a memory management unit

Describe the structure and function of a computer system, Question: a) ...

Question: a) Describe the structure and function of a computer system. b) The raw speed of a microprocessor will not achieve its potential unless a constant stream of wor

Example of prolog, Example of Prolog: We can say that this is also tru...

Example of Prolog: We can say that this is also true if there are four even numbers. Now we have our first rule: • If there are three or four even numbered cards, such play

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