Predicate in obj-C

Predicate. When switching from C ++, we began to pay attention to whether it supports C ++ STL and predicate. All of them are supported. Who makes them all supersets of C.

You can refer:

Http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/Predicates/Articles/pUsing.html#//apple_ref/doc/uid/TP40001794

 

 

DEMO code.

Nsmutablearray * array =

[Nsmutablearray arraywithobjects: @ "Miguel", @ "Ben", @ "Adam", @ "Melissa", nil];



Nspredicate * bpredicate = [nspredicate predicatewithformat: @ "Self beginswith [c] 'A'"];

Nsarray * beginwithb = [array filteredarrayusingpredicate: bpredicate];

// Beginwithb contains {@ "Adam "}.



Nspredicate * spredicate = [nspredicate predicatewithformat: @ "Self contains [c] 'E'"];

[Array filterusingpredicate: spredicate];


Nspredicate * predicate = [nspredicate predicatewithformat: @ "self in % @",

[Nsarray arraywithobjects: @ "Stig", @ "shaffiq", @ "Chris", nil];

Bool result = [predicate evaluatewithobject: @ "shaffiq"];

 

 

For more information about the Zheng ze expression, see class

Nsregularexpression class reference

: Http://developer.apple.com/library/ios/#documentation/Foundation/Reference/NSRegularExpression_Class/Reference/Reference.html