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

Differences between OSI and TCP/IP reference models, What are the main diff...

What are the main differences between OSI and TCP/ IP reference models? Explain briefly. We will be considering only on the key differences among the two references models. Th

Main drawbacks of cd-roms, Q. Main drawbacks of CD-ROMs? The main drawb...

Q. Main drawbacks of CD-ROMs? The main drawbacks of CD-ROMs are: It is read only thus can't be updated Access time is longer than that of magnetic disks. Very

Artificial neural networks, Artificial Neural Networks: However imagin...

Artificial Neural Networks: However imagine now in this example as the inputs to our function were arrays of pixels and there actually taken from photographs of vehicles such

Split bus operation - universal serial bus , Split Bus Operation - universa...

Split Bus Operation - universal serial bus :   USB 2.0 devices utilize a special protocol in the reset time that is called "chirping", to negotiate the high speed mode

What is secondary storage systems, There are various limitations of primary...

There are various limitations of primary memory like limited capacity which is its not enough to store a very large volume of data and volatility which is when power is turned off

Benefit of digital versatile disk read only memory, Q. Benefit of digital v...

Q. Benefit of digital versatile disk read only memory? The main benefit of having CAV is that individual blocks of data can be accessed at semi-random mode. So head can be move

Write short note on digital audio segments, Problem: a) Authoring tools...

Problem: a) Authoring tools consist of two basic features. First, an authoring facility for creating and editing, and second, a presentation vehicle for delivery. The authorin

What is middleware net dynamics, NetDynamics Application Server was the pri...

NetDynamics Application Server was the primary Java-based integrated software platform. The product was developed by NetDynamics Inc. As Java became the dominant development langua

With what symbolic names can be associated, Symbolic names can be associate...

Symbolic names can be associated with? Ans. With data or instruction symbolic names associated.

Differentiate concurrent and parallel executions, Differentiate concurrent ...

Differentiate concurrent and parallel executions ? The words "parallel "and "concurrent" are often used interchangeably, however they are different. Parallel execution is connec

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