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

Write a program using linq to find the sum of first 5 prime , Class Program...

Class Program { static void Main() { int[] MyPrimeNumbers = {1,2,3,5,7}; // Use the Count() and Sum() Standard Query Operators to // compute the count an whole su

What are the two aspects of locality of reference, What are the two aspects...

What are the two aspects of locality of reference? Define them. Two aspects of locality of reference are temporal aspects and spatial aspect. Temporal aspect is that a r

Explain about interrupt cycle, Q. Explain about Interrupt Cycle? On com...

Q. Explain about Interrupt Cycle? On completion of execute cycle the current instruction execution gets completed. At this point a test is made to conclude whether any enabled

Characteristics of the id process, The following is taken from the first ed...

The following is taken from the first edition of the Set Book. We have included this because we find these characteristics helpful. We will refer to them later. In addition to t

What are the events used for page headers and footers, What are the events ...

What are the events used for page headers and footers? The events TOP-OF-PAGE and END-OF-PAGE are used for pager headers and footers.

What is guard bits, What is guard bits? Guard bits are extra bits which...

What is guard bits? Guard bits are extra bits which are produced while the intermediate steps to yield maximum accuracy in the final results.

Learning weights in perceptrons, Learning Weights in Perceptrons: Furt...

Learning Weights in Perceptrons: Furthermore details are we will look at the learning method for weights in multi-layer networks next lecture. Thus the following description o

fisherpersons are not over-fishing, Prepare the Relational Tables to signi...

Prepare the Relational Tables to signify the following situation, which is defined by means of text and an Entity Relationship Diagram. Note: Do not attempt to vary the ERD. Yo

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