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 virtual memeory, What is virtual memory? How address mapping is don...

What is virtual memory? How address mapping is done in cache memory? Elaborate your answer with examples.

How online databases work, How Online Databases Work? An online or web-...

How Online Databases Work? An online or web-based database keeps data on a cloud of servers somewhere on the Internet, which is accessible by any authorized user with an Intern

Telnet services, java program for implementation of telnet services

java program for implementation of telnet services

Explain active matrix or thin film transistor technology, Q. Explain Active...

Q. Explain Active Matrix or Thin Film Transistor technology? This is known as TFT (Thin Film Transistor) technology. In this there is a transistor at every pixel acting as a r

Describe the interpretation features of vba, VBA is licensed to Microsoft a...

VBA is licensed to Microsoft and this compatible with and only Microsoft products. Code written is compiled by an intermediate language known as P-code and this is stored in hostin

Conjunctive normal form -artificial intelligence , Conjunctive Normal Form ...

Conjunctive Normal Form -artificial intelligence : For the resolution law to determine two sentences, they should both be in a normalized format known as conjunctive normal fo

What is machine.config, What is Machine.config?  Machine configuration ...

What is Machine.config?  Machine configuration file: The machine. config file contains settings that apply to the whole computer.  The machine.config, which can be found in the

Find the nyquist rate, Find the Nyquist rate for the following signals: (a)...

Find the Nyquist rate for the following signals: (a) x(t) = 5 sin 3000πt cos 4000πt (b) A binary channel with bit rate 36000 bps is available for PCM voice transmission. Fi

Decomposition model of parallel programming, The PVM system supports functi...

The PVM system supports functional and data decomposition model of parallel programming. It attaches with C, C++, and FORTRAN. The C and C++ language bindings for the PVM user inte

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