个人认为微词是个很不错的东西
1.自定义对象
@interface Person : NSObject
@property(nonatomic , copy)NSString * name;
@property(nonatomic , assign)int age;
@property (nonatomic , retain)NSArray * familys;
@end
2.简单实用（数据比较）
- (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
}
3.通配符和正则
- (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
}
4.数组的过滤1（里面的每个对象都是字符串）
- (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
}
5.数组的过滤2 （使用自定义的person类）
- (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format里面使用 “＝” 和 “＝＝”都是一样可行的)
NSPredicate *pred = [NSPredicate predicateWithFormat:@"name == 'long'"]; //相等
NSPredicate *pred = [NSPredicate predicateWithFormat:@"name == %@",@"long"]; //相等
NSPredicate *pred = [NSPredicate predicateWithFormat:@"age == %d",23]; //相等
NSPredicate *pred = [NSPredicate predicateWithFormat:@"age = 23",]; //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]);
}
6.数组过滤3（对象里面还有数据）
@property (nonatomic , retain)NSArray * familys; //person.h
- (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'"];
/*
* 字符串包含时必须为 整个字符串，不是是部分（比如 huanggai 的 huang；是有用数据的）
*/
NSPredicate *pred = [NSPredicate predicateWithFormat:@"name CONTAINS 'huanggai'"];
NSArray *array = [persons filteredArrayUsingPredicate:pred]; NSLog(@"array %@",[array description]); //打印 person2
}
