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

Determine the firewall in intranet technology, Determine the firewall in In...

Determine the firewall in Intranet technology Firewall remains the basic foundation of Internet and Intranet security, for many users getting into the corporate Intranet would

What is a linker program, What is a linker program? Ans. links the prog...

What is a linker program? Ans. links the program with other programs required for its execution is called a linker program.

How much frequency is centered in typical human voice, Typical human voice ...

Typical human voice is centered around                   Hz. (A)  200-400                                     (B)  280-3000  (C)  400-600

Explain sequential sharing, Explain Sequential sharing. Sequential s...

Explain Sequential sharing. Sequential sharing: In this technique of sharing, a file can be shared through only one program at a time, it is file accesses by P1 and P2 are

Structural hazards - computer architecture, Structural hazards - computer a...

Structural hazards - computer architecture: A structural hazard takes place when a part of the processor's hardware is required by 2 or more than two instructions at the same

How do you split hydrogen and oxygen gases, Q. How do you split Hydrogen an...

Q. How do you split Hydrogen and Oxygen gases in industrial electrolysis of water process? Answer:- In oxygen, electrolysis and hydrogen gas are produced at different elec

Define entry section and exit section, Define entry section and exit sectio...

Define entry section and exit section. The critical section problem is to design a protocol that the processes can use to cooperate. Every process must request permission to e

Determine the simulation factor- weather, Determine the simulation factor- ...

Determine the simulation factor- Weather Illustration of simulation is predicting weather (i.e. a weather forecaster). In this case we will consider what/how data is collected,

Multiple instruction and single data stream (misd), Multiple Instruction an...

Multiple Instruction and Single Data stream (MISD) In this association, multiple processing elements are structured under the control of multiple control units. Each control un

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