Bitwise operations in enumerations

Why can I use the bitwise operation of the enumeration?

1. What is a bitwise operation in an enumeration?

For example

int a = 1 << 0; 1 shift left 0-bit 1*2^0 = 1;

int b = 1 << 1; 1 shift left 1-bit 1*2^1 = 2;

int c = 1 << 2; 1 shift left 2-bit 1*2^2 = 4;

int d = 1 << 3; 1 shift left 3-bit 1*2^3 = 8;

and arithmetic

A | B

01

10

--------------

11 ==1+2

int value = A | b

NSLog (@ "%d,%d,%d,%d", Value & A,value & B,value & C,value & D);

The result of 0 is not included, and the result is 0 does not contain

Enumeration of events

[_TEXTF addtarget:self Action: @selector (text) Forcontrolevents:uicontroleventeditingdidbegin];

[_TEXTF addtarget:self Action: @selector (text) forcontrolevents:uicontroleventeditingchanged];

Merge the above two events as follows

[_TEXTF addtarget:self Action: @selector (text) forcontrolevents:uicontroleventeditingdidbegin | Uicontroleventeditingchanged];

}

Invoking a listener method

-(void) text

{

NSLog (@ "text box starts editing or text starts to change");

/*

Internal parsing whether the uicontroleventeditingdidbegin,uicontroleventeditingchanged is included

Step: 1.UIControlEventEditingDidBegin | Uicontroleventeditingchanged =x;

2, Judge NSLog (@ "%d", X & Uicontroleventeditingdidbegin); The result of 0 is not included, and the result is not 0 inclusive

*/

}

Bitwise operations in enumerations