Code Snips -

Enumerated Data Types:
enum datatypename {names, } variable;

Enumerated data types allow for the explicit assignment of values to user defined names. This provides for more eloquent code that is easier to 'code/type-in' - organize, and read. It also makes the interpretation of code to someone else easier to follow when reading for the first time.

Click HERE for the .ino file, or copy paste the example below.

//-----------------------------------------------------------------------------
// Program description: tutorial for enumerated data type
//
// 02/01/17 by: Atomkey / atomkey.net
// GitHub: Arduino Adjunct and Prototype Studio
//-----------------------------------------------------------------------------
// create an enumerated data type for readability and to set names 
// for anything that is unique to your coding paradigm. 

void clearSerialMonitor(void); // function prototype

enum day_of_week {mon = 1, tue, wed, thu, fri, sat, sun};

day_of_week dow;   // declare a variable of enumerated type day_of_week
                   // this can also be declared at the end of the type
                   // definition before the ;
                   
int test;          // an interget to play with.

// if you don't set the initial value [mon=1] of the first item in
// your enum, it will default to zero. From the first item the
// remainder increment by 1. e.g if mon = 1, then tue = 2.
// you can also set explicit and/or intermittent values. 
//   enum planets {mercury = 3, venus = 10, earth = 100, mars = 20};
// and you can apply the same value to more than one name
//   enum decision {no_, yes_, dont_care = 0};
// no_ and dont_care are both zero. yes_ is 1.

/***********************************************************************setup**/
void setup()
{
  // open the serial monitor so you can see what is going on
  Serial.begin(9600);

  dow = 0;       // oops - I've set the variable out of scope. What happens?
  test = -1;     // let's use test as a counter [see below]
  clearSerialMonitor();
}

/************************************************************************loop**/
void loop()
{
    
  // dow++; // this doesn't work becuase the ++ operator is not recognized

              // but if you want to increment this type, you can do this..
  test++;     // on first iteration this should become zero
  dow = test; // type incremented

  // dow = tuesday; // but the beauty of the enum type is to write code that
                    // looks, organizes, and reads better  
  
  switch(dow)
   {
       case 0: Serial.println("out_of_range 0"); break;
     case mon: Serial.println("Monday");         break;
     case tue: Serial.println("Tuesday");        break;
     case wed: Serial.println("Wednesday");      break;
     case thu: Serial.println("Thrusday");       break;
     case fri: Serial.println("Friday");         break;
     case sat: Serial.println("Saturday");       break;
     case sun: Serial.println("Sunday");         break;
       case 8: Serial.println("out_of_range 8"); break;
   }

 if(test >= 8)              // at the end?
  {
     delay(1500);
     test = -1;             // start from the beginning
     clearSerialMonitor();  
  }

 delay(250);                // give me a moment to read the screen
}

/**********************************************************clearSerialMonitor**/
void clearSerialMonitor(void)
{
  int line_feed = 100;  
  // blast a bunch of line feeds to the serial monitor to wipe it clear
  while(line_feed--) Serial.println();  
}

// end of code [enum_example.ino]

//========== NOTES ==========
//Enumerated data types allow for the explicit assignment of values to user defined 
//names. This provides for more eloquent code that is easier to 'code/type-in' - organize, 
//and read. It also makes the interpretation of code to someone else easier to follow 
//when reading for the first time.
//
// output:
//
//out_of_range 0
//Monday
//Tuesday
//Wednesday
//Thrusday
//Friday
//Saturday
//Sunday
//out_of_range 8

Whoa