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

Optimal number of disks , John Lindsay sells disks that have 25 software pa...

John Lindsay sells disks that have 25 software packages that show a variety of financial functions, including net present value, internal rate of return, and other financial progra

Explain working of jaz drive, Q. Explain working of Jaz Drive? Jaz Dri...

Q. Explain working of Jaz Drive? Jaz Drive: Jaz drive is a well-liked drive with 2GB and unleashes creativity of professionals in graphic design and software development, pub

Pd controller, PD controller Student should aim for Kp and Kd value that...

PD controller Student should aim for Kp and Kd value that will minimize the steady error with improved rise time and settling time. The amount of over shoot should not be more t

Hill climbing - artificial intelligence, Hill Climbing - Artificial Intelli...

Hill Climbing - Artificial Intelligence: As we've seen, in some problems, finding the search path from primary to goal state is the point of the exercise. In other problems, t

Advantages and disadvantage of message passage programming, Q. Advantages a...

Q. Advantages and Disadvantage of Message Passage Programming? Advantages of Message Passage Programming     Portable It is less error prone Offers excellent

What is blocking probability, What is blocking probability? Blocking ...

What is blocking probability? Blocking Probability: The blocking probability P is described as the probability like all the servers in system are busy. If all the servers ar

Adbms, what are the different way of executing pipelines

what are the different way of executing pipelines

State about the data glove, State about the Data Glove  Data glove is u...

State about the Data Glove  Data glove is used to grasp a "virtual" object. The glove is constructed with a series of sensors that detect hand and finger motions. Electromagnet

Target _self, TARGET = "_self" "_self" puts the new document in the s...

TARGET = "_self" "_self" puts the new document in the same window and frame as current document. "_self" works the same as if you hadn't used TARGET at all.

Period and space tradeoffs - artificial intelligence, Period and Space Trad...

Period and Space Tradeoffs - artificial intelligence: In practice, you are going to stop your agent for long term using in searching goal at some stage if it has not found a s

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