Predicate in Obj-C

Predicate,又一次看到了。從c＋＋轉過來的時候就開始關注它是否支援c＋＋的STL和predicate。看到都是支援的。誰讓他們都是C的超集呢。

可以參照：

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

 

 

示範下代碼。

    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"];

 

 

關於正澤運算式可以參照類

NSRegularExpression Class Reference

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