NSPredicate类，指定过滤器的条件－－－董鑫

    /*
     比较和逻辑运算符
     就像前面的例子中使用了==操作符，NSPredicate还支持>, >=, <, <=, !=, <>,还支持AND, OR, NOT（或写成C语言样式&&, ||, ! ），其中AND，OR，NOT还是不区分大小写的
     */
    
    NSArray *array = [NSArray array];
    
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"age <= 28"];
    for (Student *student in array) {
        //标示指定的对象是否满足谓语条件
        if ([predicate evaluateWithObject:student]) {
            NSLog(@"person name : %@",student.name);
        }
    }
    
    //返回一个符合谓语条件的数组
    NSArray *newArray = [array filteredArrayUsingPredicate:predicate];
    for (Student *student in newArray) {
        NSLog(@"person name : %@",student.name);
    }
    
    /*
     关键字 IN,BEGINSWITH,ENDSWITH,CONTAINS,LIKE,大小写都可以.添加的限制性字符串一定要添加‘‘
     */
    Student *student = [[Student alloc]init];
    
    NSPredicate *preIN = [NSPredicate predicateWithFormat:@"student.name IN {‘rose‘,‘bruse‘}"];
    NSArray *student1 = [array filteredArrayUsingPredicate:preIN];
    //以**开始beginswith
    NSPredicate *preBeginsWith = [NSPredicate predicateWithFormat:@"student.name beginswith ‘滚犊子‘"];
    NSArray *student2 = [array filteredArrayUsingPredicate:preBeginsWith];
    //以＊＊结尾endswith
    NSPredicate *preEndsWith = [NSPredicate predicateWithFormat:@"student.name endswith ‘滚犊子‘"];
    NSArray *student3 = [array filteredArrayUsingPredicate:preEndsWith];
    //包含contains
    NSPredicate *preContains = [NSPredicate predicateWithFormat:@"student.name contains ‘滚犊子‘"];
    NSArray *student4 = [array filteredArrayUsingPredicate:preContains];
    //模糊查询like
    NSPredicate *preLike = [NSPredicate predicateWithFormat:@"student.name like ‘*%@*‘",@"滚犊子"];
    NSArray *student5 = [array filteredArrayUsingPredicate:preLike];