iOS OC 谓词筛选

 //年龄小于30  
        //定义谓词对象，谓词对象中包含了过滤条件  
        NSPredicate *predicate = [NSPredicate predicateWithFormat:@"age<%d",30];  
        //使用谓词条件过滤数组中的元素，过滤之后返回查询的结果  
        NSArray *array = [persons filteredArrayUsingPredicate:predicate];  
        NSLog(@"filterArray=%@",array);  
          
        //查询name=1的并且age大于40  与&&
        predicate = [NSPredicate predicateWithFormat:@"name='1' && age>40"];  
        array = [persons filteredArrayUsingPredicate:predicate];  
        NSLog(@"filterArray=%@",array);  
    注：对于变量应使用
    predicate = [NSPredicate predicateWithFormat:@"name CONTAINS %@&& age>40",str];
  
          
        //in(包含)   或||
        predicate = [NSPredicate predicateWithFormat:@"self.name IN {'1','2','4'} || self.age IN{30,40}"];  
          
        //name以a开头的  
        predicate = [NSPredicate predicateWithFormat:@"name BEGINSWITH 'a'"];  
        //name以ba结尾的  
        predicate = [NSPredicate predicateWithFormat:@"name ENDSWITH 'ba'"];  
          
        //name中包含字符a的  
        predicate = [NSPredicate predicateWithFormat:@"name CONTAINS 'a'"];  
          
        //like 匹配任意多个字符  
        //name中只要有s字符就满足条件  
        predicate = [NSPredicate predicateWithFormat:@"name like '*s*'"];  
        //?代表一个字符，下面的查询条件是：name中第二个字符是s的  
        predicate = [NSPredicate predicateWithFormat:@"name like '?s'"];