NSPredicate的完全用法

NSPredicate描述查詢的方式，原理類似於在數據庫中進行查詢
計算謂詞：
//基本的查詢
NSPredicate *predicate;
predicate = [NSPredicate predicateWithFormat: @"name =='Herbie'"];
    BOOLmatch = [predicate evaluateWithObject: car];
    NSLog(@"%s", (match) ? "YES" : "NO");
//在整個cars裏面循環比較
    predicate= [NSPredicate predicateWithFormat: @"engine.horsepower> 150"];
    NSArray*cars = [garage cars];
    for(Car *car in [garage cars]) {
        if([predicate evaluateWithObject: car]) {
            NSLog(@"%@", car.name);
        }
    }
//輸出完整的信息
    predicate= [NSPredicate predicateWithFormat: @"engine.horsepower> 150"];
    NSArray*results;
    results= [cars filteredArrayUsingPredicate: predicate];
    NSLog(@"%@", results);
//含有變量的謂詞
    NSPredicate*predicateTemplate = [NSPredicate predicateWithFormat:@"name ==$NAME"];
    NSDictionary*varDict;
    varDict= [NSDictionary dictionaryWithObjectsAndKeys:
               @"Herbie",@"NAME", nil];
    predicate= [predicateTemplate predicateWithSubstitutionVariables:varDict];
    NSLog(@"SNORGLE:%@", predicate);
    match= [predicate evaluateWithObject: car];
  NSLog (@"%s", (match) ? "YES" :"NO");
//注意不能使用$VARIABLE作爲路徑名，因爲它值代表值
//謂詞字符竄還支持c語言中一些常用的運算符
   
    predicate= [NSPredicate predicateWithFormat:
                 @"(engine.horsepower> 50) AND (engine.horsepower <200)"];
    results= [cars filteredArrayUsingPredicate: predicate];
    NSLog(@"oop %@", results);
   
    predicate= [NSPredicate predicateWithFormat: @"name <'Newton'"];
    results= [cars filteredArrayUsingPredicate: predicate];
    NSLog(@"%@", [results valueForKey: @"name"]);
//強大的數組運算符
    predicate= [NSPredicate predicateWithFormat:
                 @"engine.horsepowerBETWEEN { 50, 200 }"];
    results= [cars filteredArrayUsingPredicate: predicate];
    NSLog(@"%@", results);
   
    NSArray*betweens = [NSArray arrayWithObjects:
                         [NSNumbernumberWithInt: 50], [NSNumber numberWithInt: 200], nil];
    predicate= [NSPredicate predicateWithFormat: @"engine.horsepower BETWEEN%@", betweens];
    results= [cars filteredArrayUsingPredicate: predicate];
    NSLog(@"%@", results);
    predicateTemplate= [NSPredicate predicateWithFormat: @"engine.horsepower BETWEEN$POWERS"];
    varDict= [NSDictionary dictionaryWithObjectsAndKeys: betweens, @"POWERS",nil];
    predicate= [predicateTemplate predicateWithSubstitutionVariables:varDict];