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

Representation scheme in artificial intelligence, Representation scheme in ...

Representation scheme in artificial intelligence: It is not hard to see why logic has been popular representation scheme in AI: In this way, It is easy to represent knowl

Binary search, Binary Search Now that the basic framework is working, ...

Binary Search Now that the basic framework is working, it is time to begin implementing a few alternative search functions. Each of these search algorithms have strengths and

What is read only memory (rom) and define the use of it?, What is Read only...

What is Read only memory (ROM) and Define the Use of it? A simple kind of ROM can be constructed from a decoder, Or gates, and a number of wires. Input

Define word length, Define word length?  Every group of n bits is refer...

Define word length?  Every group of n bits is referred to as a word of information and n is known as the word length.

Subtract, Write the Add/subtract rule for floating point numbers. Ans:...

Write the Add/subtract rule for floating point numbers. Ans: a. Select the number with the smaller exponent and shift its mantissa right a number of steps equal to the differe

Explain addressing modes in risc, Q. Explain Addressing modes in RISC? ...

Q. Explain Addressing modes in RISC? Simple addressing modes: Another benefit is the use of simple addressing modes. RISC machines employ simple register addressing having disp

Token packets - universal serial bus, Token packets in universal serial b...

Token packets in universal serial bus - computer architecture: Token packets consist of a PID byte followed by two payload bytes: a 5-bit CRC and 11 bits of address. Tokens

For what CIDR stands, CIDR stands for? CIDR stands here for Classless I...

CIDR stands for? CIDR stands here for Classless Inter Domain Routing.

State the tips of timescale directive, State the Tips of timescale directiv...

State the Tips of timescale directive Include a `timescale directive at the top of each module, even if there are no delays i n the module, since some simulators may require th

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