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 the purpose of the enableevents() method, The enableEvents() method...

The enableEvents() method is used to enable an event for a certain object. Normally, an event is enabled when a listener is added to an object for a certain event. The enableEvents

What is the difference between thread and process, What is the difference b...

What is the difference between thread and process?  Thread - is used to execute more than one program at a time. process - executes single program A thread is a path of e

Microprocessor, what is opcode for addition and subtraction

what is opcode for addition and subtraction

?????, c program??????????

c program??????????

Determine the binary equivalent of hexadecimal FA, The binary equivalent of...

The binary equivalent of (FA) 16   is ? Ans. (FA) 16 = (11111010) 10

An 8086 interrupt, An 8086 interrupt can take placedue to the following rea...

An 8086 interrupt can take placedue to the following reasons: 1.  Hardware interrupts caused by some external hardware device. 2.  Software interrupts that can be invoked wit

Configure port to send logic, Configure port A for the lower 4 bits to be i...

Configure port A for the lower 4 bits to be inputs and the upper 4 bits to be outputs. The program should chase a logic one from Pa4 -> Pa7, depending upon the condition of Pa0-Pa3

Name of all sap databases, All SAP Databases are Relational Databases ...

All SAP Databases are Relational Databases is the all sap databases.

Classify process and differentiate program, Classify Process, differentiate...

Classify Process, differentiate program, process A process maybe concerned to be a program being run. A program isn't a process of itself; it's a passive Entity while the proce

Why timing signal distributor required, Q. Why Timing Signal Distributor r...

Q. Why Timing Signal Distributor required? What do you mean by Memory Cycle? How many Memory Cycles required for following instructions: 1. ADD 2. CLEAR and ADD 3. DC

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