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 is enctype, ENCTYPE="application/x-www-form-urlencoded" and in its pl...

ENCTYPE="application/x-www-form-urlencoded" and in its place use ENCTYPE="text/plain". The subsequent illustration displays a general form which includes some of the commo

Explain high level data link control, Explain High Level Data Link Control....

Explain High Level Data Link Control. HDLC - it is High Level Data Link Control: Protocol Overall explanation: Layer 2 of the OSI model is the data link layer. One of the

What is the type of process identifiers, What is the type of Process Identi...

What is the type of Process Identifiers? Identification of the real user Identification of the effective user Identification of the real group Identification

Show the shared programming using library routines, Q. Show the Shared Prog...

Q. Show the Shared Programming Using Library Routines? The mainly well-liked of them is use of combo function known as fork() and join(). Fork() function is used to initialize

How can we send data to external programs, How can we send data to external...

How can we send data to external programs? Using SPA/GPA parameters(SAP memory). Using EXPORT/IMPORT data (ABAP/4 memory)

Term memory as used in a computer context initially, Term memory as used in...

Term memory as used in a computer context initially The term memory as used in a computer context initially referred to magnetic core memory devices which were used beginning

Explain about dual in line memory modules, Q. Explain about Dual In line Me...

Q. Explain about Dual In line Memory Modules? A DIMM is capable of delivering 64 data bits right away. Usual DIMM capacities are 64MB and up. Every DIMM has 84 gold patted conn

What is synchronous reset, What is Synchronous reset? Synchronous reset...

What is Synchronous reset? Synchronous reset: Synchronous reset logic will synthesize to smaller flip-flops, mainly when the reset is gated along with the logic generating t

What is shared memory programming, Q. What is Shared Memory Programming? ...

Q. What is Shared Memory Programming? We know all processors share a common memory in shared memory model. Every processor can be assigned a separate portion of program stored

what is code for adding two integers in java?, import java.util.Scanner;  ...

import java.util.Scanner;   class AddNumbers {    public static void main(String args[])    {       int x, y, z;       System.out.println("Enter two integers to calculate their sum

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