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

Define alphabet and string, Define Alphabet and String? A finite set of...

Define Alphabet and String? A finite set of symbols is termed as alphabet. An alphabet is frequently signified by sigma, yet can be specified any name. B = {0, 1} here B is

Describe about the database marketing application of olap, Database marketi...

Database marketing tool or application helps a user or marketing professional in determining the right tool or plan for his valuable add campaign. This tool haves data from all sou

Draw the logic circuit of Decimal to BCDencoder, What is an encoder? Draw t...

What is an encoder? Draw the logic circuit of Decimal to BCD encoder and explain its working. Ans. Encoder: It is a combinational logic circuit which converts alphanumeric ch

Differentiate between adaptive and non-adaptive routing, Differentiate betw...

Differentiate between adaptive and non-adaptive routing. Adaptive routing defines the ability of a system, by which routes are characterised through their destination, to cha

How is transaction processing system affected, How is Transaction Processin...

How is Transaction Processing System affect performance of e-commerce sites? Transaction Processing System influences performance of e-commerce sites: Transaction-Processing

What is called static and dynamic branch prediction, What is called static ...

What is called static and dynamic branch prediction? The branch prediction decision is always the similar every time a given instruction is implemented. Any approach that has t

Learning weights in perceptrons, Learning Weights in Perceptrons - Artifici...

Learning Weights in Perceptrons - Artificial neural network In detail we will look at the learning method for weights in multi-layer networks next chapter. The following descri

Give brief description about arithmetic processing unit, Give brief descrip...

Give brief description about arithmetic processing unit To execute the arithmetic operations there is a separate section known as arithmetic processing unit in CPU. The arithme

Why dynamic RAMs require refreshing, Explain briefly, why dynamic RAMs requ...

Explain briefly, why dynamic RAMs require refreshing? Ans: Due to the charge's natural tendency to distribute itself in a lower energy-state configuration that is, the charg

Carry save addition and generated and propagate function, Explain carry sav...

Explain carry save addition (CSA) process. Ans: Instead of allowing the carries ripple along the rows, they can be saved and then introduced into the next roe at the right wei

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