谓词(过滤)

@interface Person : NSObject@PRoperty(nonatomic , copy)NSString * name;@property(nonatomic , assign)int age;@property (nonatomic , retain)NSArray * familys;@end

- (void)testObject1 {    Person *person = [[Person alloc] init];    person.name = @"gulong";    person.age = 24;   //整形比较    NSPredicate * pred = [NSPredicate predicateWithFormat:@"age > 25"];    BOOL match = [pred evaluateWithObject:person];    NSLog(@"%s",(match)?"YES":"NO");
   //printf: NO}

- (void)testObject2 {    /*      BEGINSWITH：检查某个字符串是否以另一个字符串开头。     ENDSWITH：检查某个字符串是否以另一个字符串结尾。     CONTAINS：检查某个字符串是否以另一个字符串内部。     [c]不区分大小写[d]不区分发音符号即没有重音符号[cd]既不区分大小写，又不区分发音符号。     */    Person *person = [[Person alloc] init];    person.name = @"gulong";    person.age = 24;        /* 通配符 */    NSPredicate *predicate1 = [NSPredicate predicateWithFormat:@"name LIKE[cd] '*er*'"];         //*代表通配符Like还接受[cd].    predicate1 = [NSPredicate predicateWithFormat:@"name LIKE[cd] '???er*'"];    //?只匹配一个字符并且还可以接受[cd].    //*表示有多个占位符    /* 正则匹配 */    NSString *regex = @"[A-Za-z]+";    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];        if ([predicate evaluateWithObject:@"huang"]) {        NSLog(@"字符串是否为纯字母");    }    //printf 字符串是否为纯字母

}

- (void)testArray1 {    NSArray *array = [[NSArray alloc]initWithObjects:@"beijing",@"shanghai",@"guangzou",@"wuhan", nil];    NSString *string = @"ang";  //获取带有ang的所有字符串，然后形成一个数组    NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF CONTAINS %@",string];    NSLog(@"%@",[array filteredArrayUsingPredicate:pred]);    //printf: shanghai,guangzou}

- (void)testArray2 {    Person *person1 = [[Person alloc] init];    person1.name = @"long";    person1.age = 23;        Person *person2 = [[Person alloc] init];    person2.name = @"gu";    person2.age = 23;        Person *person3 = [[Person alloc] init];    person3.name = @"long";    person3.age = 24;    NSArray *persons = @[person1,person2,person3];    //直接使用对象里面的属性就可以了，不能使用数组的某个对象名（其实    NSPredicate *pred = [NSPredicate predicateWithFormat:@"name == 'long'"]; //相等    // (age > 23) AND (age < 26)   AND 两者都要满足，OR 两种满足其一就可    // age between {23,26}   从23 到26之间    //@"name IN { 'Herbie', 'Snugs', 'Badger', 'Flap' }"; //包含在其中用IN    NSArray *array = [persons filteredArrayUsingPredicate:pred];    NSLog(@"array %@",[array description]);    }

- (void)testArray3 {    Person *person1 = [[Person alloc] init];    person1.name = @"huang";    person1.age = 23;    person1.familys = @[@"zhuge",@"zhangfei",@"liubei"];        Person *person2 = [[Person alloc] init];    person2.name = @"gu";    person2.age = 23;    person2.familys = @[@"suiquan",@"huanggai",@"lusun"];        Person *person3 = [[Person alloc] init];    person3.name = @"huang";    person3.age = 24;    person3.familys = @[@"caochao",@"xiahou",@"caozhi"];        NSArray *persons = @[person1,person2,person3];    /*     * 数组包含时必须为 整个字符串，不是是部分（比如 huanggai 的 huang；这样是无数据的）     */    NSPredicate *pred = [NSPredicate predicateWithFormat:@"familys CONTAINS 'huanggai'"];    NSArray *array = [persons filteredArrayUsingPredicate:pred];    NSLog(@"array %@",[array description]);  //打印 person2}