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

Describe the various characteristics of udp protocol, Describe the various ...

Describe the various characteristics of UDP protocol. The characteristics of the UDP are as follows: End to end: UDP is transport protocols that can distinguish between

What are the disadvantages of a smart card, What are the disadvantages of a...

What are the disadvantages of a Smart Card? Disadvantages of Smart Cards are as follows: a. The value of money can be depleted and recharged. b. Customers should keep

Illustrate benefits of register addressing mode, Q. Illustrate benefits of ...

Q. Illustrate benefits of register addressing mode? The key benefits of register addressing are: Register access is faster than memory access and henceforth register add

Explain hybrid network in standard telephone hand set, Explain Hybrid Netwo...

Explain Hybrid Network in Standard Telephone hand set. Hybrid network: The hybrid network (sometimes termed as a duplex coil or hybrid coil) in a telephone set is a particula

Displaying the towers of hanoi solution, Once you have a solution to the To...

Once you have a solution to the Towers of Hanoi problem, we want to improve the display of the solution. The details of the implementation are up to you. At a minimum, your impleme

Give a simple example of dynamic modelling, Give a simple example of dynami...

Give a simple example of dynamic modelling using these notation A simple example using these notation is shown below in Figure:

Explain the terms topology used in lans, Explain the terms topology used in...

Explain the terms topology used in LANs. (i) LAN topologies: This network topology is a physical schematic that shows interconnection of the several users. There are four fun

What is boyce codd normal form, A relation schema R is in BCNF with respect...

A relation schema R is in BCNF with respect to a set F of functional dependencies if for all functional dependencies in F+ of the form a->b, where a and b is a subset of R, at leas

Difference between overlay graph and correlate graph, Overlay Graph: It ove...

Overlay Graph: It overlay the content of two graphs that shares an ordinary x-axis. Left Y-axis on the merged graph show's the present graph's value & Right Y-axis illustrate the v

Smli firewalls are different from the conventional, SMLI firewalls are diff...

SMLI firewalls are different from the conventional The SMLI firewalls are different from the conventional "stand in" proxies in a way that the stand-in proxies are used for 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