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 new services of cpu based exchange, Explain new services of  CPU B...

Explain new services of  CPU Based Exchange. These new services are termed as supplementary services and several of the prominent ones are given below as:  Category 1:

What are the different types of computer networks, Q. Mention different cla...

Q. Mention different classes of computer networks (on the basis of scale) and distinguish one from the other. Ans: Local Area Network (LAN) Metropolitan Area Netw

Describe thead, Q. Describe THEAD, TBODY and TFOOT tag? THEAD, TBODY, ...

Q. Describe THEAD, TBODY and TFOOT tag? THEAD, TBODY, TFOOT , , and form groups of rows. specifies that a group of rows are heade

List-processing without using suppress-dialog, What happens if we use Leave...

What happens if we use Leave to list-processing without using Suppress-Dialog? If we don't use Suppress-Dialog to next screen will be viewed but as empty, when the user presse

Shell script, shell script to find whether the given number is Armstrong or...

shell script to find whether the given number is Armstrong or not

Define overflow, Define Overflow.  An overflow is a problem in digital ...

Define Overflow.  An overflow is a problem in digital computer due to the width of registers is finite. A result that contains n+ 1 bit cannot be accommodated in a register wit

Illustration of a demon program, Q. Illustration of a demon program? Wh...

Q. Illustration of a demon program? When the PVM initialize it inspects the virtual machine in that it's to operate and creates a process known as PVM demon or simply pvmd on e

Virtulization, Analyse the future of Operating Systems with reference to Vi...

Analyse the future of Operating Systems with reference to Virtualisation.words accepted#

Pipeline, where can I find detailed explanation of 6 stage and 7 stage pipe...

where can I find detailed explanation of 6 stage and 7 stage pipeline ??

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