• 1223.2——数组的相关操作


    #import <Foundation/Foundation.h>
    #import "Person.h"
    #import "Dog.h"

    int main(int argc, const char * argv[]) {
        @autoreleasepool {
            Person *xw = [[Person alloc] init];
            Person *zs = [[Person alloc] init];
            Dog *ww =[[Dog alloc] init];
            Dog *hz =[[Dog alloc] init];
            
            //数组的创建
            NSArray *array = @[@"pxd", xw, zs, ww, hz];
            NSArray *array2 = @[array, @"zp", @"wc"];
            NSLog(@"%@", array2);
            
            //创建一个空的数组
            NSArray *array3 = [NSArray array];
            NSArray *array4 = [[NSArray alloc] init];
            
            NSArray *array5 = [NSArray arrayWithArray:array];
            NSArray *array6 = [[NSArray alloc] initWithArray:array];
            
            NSArray *array7 = [NSArray arrayWithObject:xw];
            
            //创建的时候初始化一部分数据
            //数据结尾为nil 不能向数组里面添加一个值为nil的对象
            NSArray *array8 = [NSArray arrayWithObjects:xw, zs, nil];
            NSArray *array8_1 = [[NSArray alloc] initWithObjects:xw, zs, nil];
            NSLog(@"....%@", array8);
            
            //1.获取数组元素个数 count
            NSLog(@"the count of array8 is %ld", [array8 count]);
            
            //2.访问数组里面的某个元素 使用索引值访问index
            Person *temp = [array8 objectAtIndex:0];
            
            //3.获取数组里面的最后一个元素
            Person *temp2 = [array8 lastObject];
            Person *temp3 = [array8 firstObject];
            
            //4.如何遍历一个数组
            for (int i = 0; i < array8.count; i++){
                NSLog(@"%@", [array8 objectAtIndex:i]);
            }
            
            //使用快速循环
            for (Person *p in array8){
                NSLog(@"%@", p);
            }
            
            //获取一个对象的索引值
            NSInteger index = [array8 indexOfObject:@"pxdafafa"];
            NSLog(@"index:%ld", index);
            
            //判断数组里面是否包含某个元素
            if ([array8 containsObject:@"pxdadfafa"]) {
                NSLog(@"YES");
            } else{
                NSLog(@"NO");
            }
            
            //NSMutableArray可变数组
            NSMutableArray *marray1 = [NSMutableArray array];
            NSMutableArray *mArray = [NSMutableArray arrayWithCapacity:3];
            
            //增加一个元素
            [mArray addObject:xw];
            [mArray addObject:zs];
            
            //交换元素
            [mArray exchangeObjectAtIndex:0 withObjectAtIndex:1];
            
            //插入一个元素
            [mArray insertObject:array5 atIndex:0];
            NSLog(@"%@", mArray);
            
            //删除一个元素
            [mArray removeObject:xw];
            [mArray removeObjectAtIndex:0];
            NSLog(@"%@", mArray);
            
            //删除所有
            [mArray removeAllObjects];
            
        }
        return 0;
    }

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  • 原文地址:https://www.cnblogs.com/damonWq/p/5071068.html
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