Objective-c 集合对象

　　集合（NSSet）是一组单值对象的组合，集合对象的操作包括：搜索，添加，删除集合中的成员（可变集合的功能），比较两个集合，计算两个集合的交集，并集等。

　　下面来看下（NSSet）的方法：

　　

　　1）集合的构建

　　

// 构建集合的三种方法

#import <Foundation/Foundation.h>

int main(int argc , const char *argv[]){
    @autoreleasepool {
        NSSet *set1 = [NSSet setWithObjects:@"zhangsan",@"lisi",@"wangwu",nil];
        for(NSString *temp1 in set1){
            NSLog(@"temp1 = %@",temp1);
        }
        
        NSArray *array = @[@"aa",@"bb",@"cc"];
        NSSet *set2 = [NSSet setWithArray:array];
        for(NSString *temp2 in set2)
            NSLog(@"temp2 = %@",temp2);
        
        NSSet *set3 = [[NSSet alloc] initWithObjects:@"aa",@"bb"@"cc",nil];
        for(NSString *temp3 in set3)
            NSLog(@"temp3 = %@",temp3);
    }
}

　　2）集合的遍历

　　

#import <Foundation/Foundation.h>

@interface NSString (print)

- (void)print;
- (void)show:(NSString *)str;

@end

@implementation NSString (print)

- (void)print{
    NSLog(@"%@",self);
}
- (void)show:(NSString *)str{
    NSLog(@"%@ : %@",str,self);
}

@end
int main(int argc , const char *argv[]){
    @autoreleasepool {
        NSSet *set = [NSSet setWithObjects:@"zhangsan",@"lisi",@"wangwu",nil];
        for(NSString *temp in set)
            NSLog(@"temp = %@",temp);
        
        NSLog(@"--------------------------");
        [set enumerateObjectsUsingBlock:^(id obj, BOOL *stop) {
            NSLog(@"obj = %@",obj);
        }];
        
        NSLog(@"---------------------------");
        [set makeObjectsPerformSelector:@selector(print)];
        
        NSLog(@"----------------------------");
        [set makeObjectsPerformSelector:@selector(show:) withObject:@"this is "];
        
        NSLog(@"-----------------------------");
        NSEnumerator *emr = [set objectEnumerator];
        NSString *temp = nil;
        while(temp = [emr nextObject])
            NSLog(@"temp = %@",temp);
    }
    return 0;
}

 3) 集合的比较

　　

#import <Foundation/Foundation.h>

int main(int argc , const char *argv[]){
    @autoreleasepool {
        NSSet *set = [NSSet setWithObjects:@"zhangsan",@"lisi",@"wangwu",nil];
        for(NSString *temp in set)
            NSLog(@"temp = %@",temp);
        
        BOOL ishas = [set containsObject:@"lisi"];
        if(ishas)
            NSLog(@"has lisi");
        else
            NSLog(@"no lisi");
        
        NSString *str = [set member:@"aaaa"];
        NSLog(@"str = %@",str);
        
        NSSet *set2 = [set setByAddingObject:@"xiaoliu"];
        NSLog(@"set2 = %@",set2);
        
        NSSet *set3 = [set setByAddingObjectsFromArray:@[@"aa",@"bb",@"cc"]];
        NSLog(@"set3 = %@",set3);
        
        NSSet *set4 = [NSSet setWithObjects:@"zhangsan",@"lisi",nil];
        BOOL issub = [set4 isSubsetOfSet:set];
        if(issub)
            NSLog(@"set4 is set sub class");
        else
            NSLog(@"set4 no set sub class");
        
        BOOL isinterset = [set intersectsSet:set4];
        if(isinterset)
            NSLog(@"set and set4 has intersect");
        else
            NSLog(@"set and set4 no intersect");
        
        BOOL isequal = [set isEqualToSet:set2];
        if(isequal)
            NSLog(@"set = set2");
        else
            NSLog(@"set != set2");
        
    }
    return 0;
}

　　4）可变集合(NSMutable)

　　

　　下面通过一个例子来说可变集合的用法：

　　

#import <Foundation/Foundation.h>

@interface NSString (print)
-(void)print;
-(void)show:(NSString *)str;
@end

@implementation NSString(print)
-(void)print{
    NSLog(@"%@",self);
}
-(void)show:(NSString *)str{
    NSLog(@"%@ : %@",str,self);
}
@end

int main(int argc,char **argv){
    @autoreleasepool {
        NSMutableSet *mset = [NSMutableSet setWithObjects:@"zhangsan",@"lisi",@"wangwu", nil];
        
        [mset addObject:@"zhaoliu"];
        NSLog(@"mset = %@",mset);
        
        [mset addObjectsFromArray:@[@"111",@"222",@"333"]];
        NSLog(@"mset = %@",mset);
        
        [mset removeObject:@"111"];
        NSLog(@"mset = %@",mset);
        
        NSSortDescriptor *sortdesr = [[NSSortDescriptor alloc] initWithKey:nil ascending:YES];
        NSArray *sortset = [mset sortedArrayUsingDescriptors:@[sortdesr]];
        NSLog(@"mset sort = %@",sortset);
        
        NSArray *array = [mset allObjects];
        NSLog(@"array = %@",array);
        NSSet *set2 = [NSSet setWithArray:array];
        NSLog(@"set2 = %@",set2);
        
        NSString *str = [mset anyObject];
        NSLog(@"str = %@",str);
        
        [mset setSet:set2];
        NSLog(@"mset = %@",mset);
        
        [mset removeAllObjects];
        NSLog(@"mset = %@",mset);
    }
}