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bookSymbolic Constant

Each #define line consists of three parts:

The body of a macro can be not only a single numeric value, but also other macros or entire expressions:

main.c

main.c

copy

              
12345678910

            
#include <stdio.h>
#define TWO 2                                // macros with value.
#define RESULT TWO*TWO                       // TWO is replaced by the number 2.
#define PRINT printf("result = %d", RESULT);

int main() 
{
   PRINT 
   return 0;
}

Every time the compiler encounters “TWO”, it will simply substitute its value 2.

The macro is immutable. Once defined, it is a permanent textual substitution within the file or scope where it is defined.

Why do we need this? Why not just use variables?

What is better to use?:

  • If the value never changes, const is better, because it is safer;
  • If you need to substitute a simple number or text, you can use a macro.
  1. Create an object macro add, the body of the macro is an addition operator +.
  2. Use a macro to add any two numbers.
Oppgave

Swipe to start coding

  1. Create an object macro add, the body of the macro is an addition operator +;
  2. Use a macro to add any two numbers.

Løsning

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bookSymbolic Constant

Sveip for å vise menyen

Each #define line consists of three parts:

The body of a macro can be not only a single numeric value, but also other macros or entire expressions:

main.c

main.c

copy

              
12345678910

            
#include <stdio.h>
#define TWO 2                                // macros with value.
#define RESULT TWO*TWO                       // TWO is replaced by the number 2.
#define PRINT printf("result = %d", RESULT);

int main() 
{
   PRINT 
   return 0;
}

Every time the compiler encounters “TWO”, it will simply substitute its value 2.

The macro is immutable. Once defined, it is a permanent textual substitution within the file or scope where it is defined.

Why do we need this? Why not just use variables?

What is better to use?:

  • If the value never changes, const is better, because it is safer;
  • If you need to substitute a simple number or text, you can use a macro.
  1. Create an object macro add, the body of the macro is an addition operator +.
  2. Use a macro to add any two numbers.
Oppgave

Swipe to start coding

  1. Create an object macro add, the body of the macro is an addition operator +;
  2. Use a macro to add any two numbers.

Løsning

Switch to desktopBytt til skrivebordet for virkelighetspraksisFortsett der du er med et av alternativene nedenfor
Alt var klart?

Hvordan kan vi forbedre det?

Takk for tilbakemeldingene dine!

close

Awesome!

Completion rate improved to 5.56
Seksjon 2. Kapittel 1
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