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

Explain virtual address, What is virtual address? The binary address th...

What is virtual address? The binary address that the processor used for either instruction or data known as virtual address.

Subtraction of 01100-00011 using 2's complement method, Subtraction of 0110...

Subtraction of 01100-00011 using 2's complement method Ans. Firstly 1's complement of 00011 is 11100 and 2's complement is 11100 + 1 = 11101. Thus If a last carry is

How does the internet work, Every computer connected to Internet has a uniq...

Every computer connected to Internet has a unique address. Let's just say your IP address is 1.2.3.4 and you want to send a message to computer with IP address 5.6.7.8. Message you

How can we decrement and increment operations, How can we decrement and in...

How can we decrement and increment  operations We  can  implement decrement  and increment  operations  by  using  a  combinational circuit  or  binary  down/up counters.  In

What is an arithmetic processor, Q. What is an arithmetic processor? A ...

Q. What is an arithmetic processor? A distinctive CPU necessitates most of the control and data processing hardware for implementing non-arithmetic functions. As the hardware c

Analysis of algorithms, Analysis of Algorithms For this task, each stu...

Analysis of Algorithms For this task, each student should do two things: An empirical analysis of the runtime and comparisons made for all algorithms as a function of input si

#title.linear programming, zmax=7.5x1-3x2 subject to constraints 3x1-x2-x3>...

zmax=7.5x1-3x2 subject to constraints 3x1-x2-x3>=3 x1-x2+x3>=2 x1,x2,x3>=0

Weighted harmonic mean and geometric mean, Problem Show which of the w...

Problem Show which of the weighted arithmetic mean, geometric mean or harmonic mean, you would use in each of the following case. Justify your answer in each case. (a)

Binary resolution, Binary Resolution: However we saw unit resolution f...

Binary Resolution: However we saw unit resolution for a propositional inference rule in the previous lecture:  (A?  B,   ¬B) /A Thus we can take this a little further to

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