蓝鸥iOS从零基础到精通就业－OC语言入门 集合

• iOS从零基础到精通就业 Objective-C
  

• CSDN观看地址：http://edu.csdn.net/course/detail/3347
• 集合
  

• #import <Foundation/Foundation.h>int main(int argc, const char * argv[]) {           //不可变集合    //跟字典一样没有顺序    //去除重复的元素    //NSSet *set1 = [[NSSet alloc] initWithObjects:<#(nonnull id), ...#>, nil];    NSSet *set1 = [NSSet setWithObjects:@"aaa",@"bbb",@"ccc",@"ddd",@"aaa",@"ccc", nil];    NSLog(@"%@",set1);    //获取集合中的元素    NSString *str = [set1 anyObject];    NSLog(@"%@",str);        //可变集合    NSMutableSet *mSet = [NSMutableSet set];    [mSet addObject:@"1111"];    [mSet addObject:@"2222"];    [mSet addObject:@"3333"];    [mSet addObject:@"4444"];    [mSet addObject:@"1111"];    NSLog(@"%ld",[mSet count]);        [mSet removeObject:@"3333"];    NSLog(@"%ld",[mSet count]);        //计数集合    NSCountedSet *cSet = [NSCountedSet set];    [cSet addObject:@"1111"];    [cSet addObject:@"2222"];    [cSet addObject:@"3333"];    [cSet addObject:@"4444"];    [cSet addObject:@"1111"];    [cSet addObject:@"1111"];    [cSet addObject:@"2222"];    [cSet addObject:@"1111"];    [cSet addObject:@"1111"];    NSLog(@"%ld",[cSet countForObject:@"1111"]);            int a = 10;    int b = 20;    NSString *astr = [NSString stringWithFormat:@"%d",a];    NSString *bstr = [NSString stringWithFormat:@"%d",b];        NSArray *array = [NSArray arrayWithObjects:astr,bstr, nil];        NSString *result = [array objectAtIndex:0];    int a1 = [result intValue];    NSLog(@"%d",a1);        float f1 = 9.99;    NSNumber *n1 = [NSNumber numberWithFloat:f1];    NSArray *array1 = @[n1];    NSNumber *resultNumer = array1[0];    float resultFloat = [resultNumer floatValue];        return 0;}