enum type

[Cutefriendzoned]

Hey guys , so I've been reading about enum , but I never got what's the point from it ? does programmers use it a lot ?

after reading the topic what I learned is that it used to know how many memory it should use for a variable , and it increases by 1 unless it's declared.

I'm the type of guy that loves to learn in action " apply it by making a small program to get the idea " but in the book I didn't really understand what the idea behind it ?

[maeriden]

The point of enum is to define constant values. Its purpose is a lot like #define, but it has some advantages, like the fact that it's not a preprocessor directive and it can automatically increment the value of the constants.

For example, when you press a key on the keyboard, a numerical code representing the key is sent to your application. Since it's difficult to remember all the codes you can set up an enum that goes like this

enum keyCodes {
    KEY_A = 1,
    KEY_B, //Automatically set to 2
    //etc
    KEY_Z, //Incremented automatically to 26
    KEY_SPACE = 50, //Explicitly set to 50. 27-49 will not be used unless you say so. The next will be 51
    //etc
}

When you write code to respond to key presses you won't have if(key == 8) but if(key == KEY_H). It's a lot more readable and saves you the time of looking up which key corresponds to 8.

[IceThatJaw]

Enums can be used to group global constants that are also integral so they can be used easily in switches, iterations, or even in arithmetic.

[JLBorges]

The primary advantage of named enumerations over named integral constants is that they enforce type safety.

enum colour { RED = 1, GREEN = 2, BLUE = 4 /* ... */ } ;

enum month { JAN = 1, FEB, MAR, APR = 4  /* ... */, DEC } ;

colour clr_sky = BLUE ; // fine

clr_sky = APR ; // *** error: APR is not the same as BLUE

void print( colour clr ) { /* print the name of the colour */ } // overload one

void print( month m ) { /* print the name of the month */ } // overload two

void print( int i ) { /* print the value of the integer */ } // overload three 

[Cutefriendzoned]

Thank you guys , you helped a lot ^^