OC语言基础之NSArray

 

 

0.数组的分类

NSArray :不可变数组
NSMutableArray : 可变数组

   1:  // @[] 只创建不可变数组NSArray
   2:      /* 错误写法
   3:      NSMutableArray *array = @[@"jack", @"rose"];
   4:  
   5:      [array addObject:@"jim"];
   6:      */
   7:      
   8:      
   9:      //NSArray *array = @[@"jack", @"rose"];

 

1.数组的创建

   1:  //    char s[8];
   2:      //    NSArray
   3:      // c语言里数组只能放定义时类型元素
   4:      // NSArray 可用放置各种类型对象
   5:      //NSArray *array = [NSArray array];
   6:      //NSArray *array1 = [NSArray arrayWithObject:@"12"];
   7:      NSArray *array2 = [NSArray arrayWithObjects:@"1", @"2", @"3", nil];
   8:      //NSArray *array3 = [NSArray arrayWithArray:array2];
   9:      
  10:      
  11:      //NSUInteger count = [array2 count];
  12:      //BOOL isContain = [array2 containsObject:@"22"];
  13:      //    NSLog(@"%d", isContain);
  14:      //id lastObj = [array2 lastObject];
  15:      
  16:      //    char s[8];
  17:      //    s[1]
  18:      //    id obj = [array2 objectAtIndex:0];
  19:      //    NSLog(@"%@", obj);
  20:      //    NSUInteger index = [array2 indexOfObject:@"2"];
  21:      //    NSLog(@"%zd", index);
  22:      
  23:      //    NSUInteger index = [array2 indexOfObject:@"3" inRange:NSMakeRange(0, 3)];
  24:      //    if (NSNotFound == index) {
  25:      //        NSLog(@"在0,2没有找到");
  26:      //    }else{
  27:      //        NSLog(@"找到了");
  28:      //    }

 

 

2.数组的常用操作

1)可变数组

   1:  //    NSMutableArray *array = [[NSMutableArray alloc] initWithCapacity:10];
   2:  //
   3:      NSMutableArray *array = [NSMutableArray array];
   4:      NSArray *array1 = [NSArray arrayWithObjects:@"1", @"2", @"3", nil];
   5:      [array setArray:array1];
   6:      
   7:      [array addObject:@"4"];
   8:      
   9:      // 1,2,3,4
  10:  //    [array removeObject:@"4"];
  11:  //    [array removeObjectAtIndex:3];
  12:  //    [array removeAllObjects];
  13:      
  14:  //    [array insertObject:@"11" atIndex:1];
  15:      // 1 11 2..
  16:  //    [array removeLastObject];
  17:  //    NSLog(@"%@", array);
  18:  //    [array replaceObjectAtIndex:0 withObject:@"11"];
  19:      
  20:      [array exchangeObjectAtIndex:0 withObjectAtIndex:1];
  21:      NSLog(@"%@", array);

2)读写文件

   1:   // 写入文件
   2:      //    NSArray *array = [NSArray arrayWithObjects:@"1", @"2", @"3", nil];
   3:      //    NSString *path = @"//Users/apple/Desktop/1.txt";
   4:      //    BOOL isSucess = [array writeToFile:path atomically:YES];
   5:      //    if (isSucess) {
   6:      //        NSLog(@"写入成功");
   7:      //    }else{
   8:      //          NSLog(@"写入失败");
   9:      //    }
  10:      
  11:      NSString *path = @"//Users/apple/Desktop/1.txt";
  12:      NSArray *array = [NSArray arrayWithContentsOfFile:path];
  13:      NSLog(@"%@", array);

3)和NSString相关的操作

   1:   NSArray *array = [NSArray arrayWithObjects:@"1", @"2", @"3", nil];
   2:      NSString *str = [array componentsJoinedByString:@"="];
   3:      
   4:      // 1=2=3
   5:      NSArray *array1 =[str componentsSeparatedByString:@"="];
   6:      NSLog(@"%@", array1);

 

 

 

4)数组的截取

   1:    NSArray *array = [NSArray arrayWithObjects:@"1", @"2", @"3", nil];
   2:      NSArray *array1 = [array arrayByAddingObject:@"4"];
   3:      //NSLog(@"%@ ===== %@", array, array1);
   4:      NSArray *array2 = [array subarrayWithRange:NSMakeRange(0, 2)];
   5:      NSLog(@"%@", array2);

 

5)数组的遍历

   1:  //NSArray *array = [NSArray arrayWithObjects:@"1", @"2", @"3", nil];
   2:      
   3:      // 普通遍历
   4:      //    for (int i=0; i<array.count; i++) {
   5:      //        id obj = [array objectAtIndex:i];
   6:      //        NSLog(@"%@", [obj description]);
   7:      //
   8:      //        if (1 == i) {
   9:      //            break;
  10:      //        }
  11:      //    }
  12:      
  13:      // 快速遍历
  14:      //    int i = 0;
  15:      //    for (id obj in array) {
  16:      //        NSLog(@"%@", [obj description]);
  17:      //
  18:      //        i++;
  19:      //        if (2==i) {
  20:      //            break;
  21:      //        }
  22:      //    }
  23:      
  24:      // block遍历
  25:      //    [array enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
  26:      //        NSLog(@"%@", [obj description]);
  27:      //
  28:      //        if (1==idx) {
  29:      //            (*stop) = YES;
  30:      //        }
  31:      //    }];
  32:      
  33:      Dog *dog = [[Dog alloc] init];
  34:      Dog *dog1 = [[Dog alloc] init];
  35:      NSArray *array = [NSArray arrayWithObjects:dog, dog1, nil];
  36:      [array makeObjectsPerformSelector:@selector(eat:) withObject:@"骨头"];

 

 

4)可变数组的基本使用

   1:  NSMutableArray *array = [NSMutableArray arrayWithObjects:@"rose", @"jim", nil];
   2:      
   3:      // 添加元素
   4:      [array addObject:[[Person alloc] init]];
   5:      
   6:      [array addObject:@"jack"];
   7:      
   8:      // 删除元素
   9:      //[array removeAllObjects];
  10:      // 删除指定的对象
  11:      // [array removeObject:@"jack"];
  12:      [array removeObjectAtIndex:0];
  13:      
  14:      // 错误写法
  15:      // [array addObject:nil];
  16:      
  17:      
  18:      NSLog(@"%@", array);
  19:      
  20:      NSLog(@"%ld", array.count);

 

5)其他的一些方法

   1:    
   2:      /*
   3:       1.NSArray的创建
   4:       */
   5:      NSArray *array2 = [NSArray arrayWithObject:@"jack"];
   6:      
   7:      // nil是数组元素结束的标记
   8:      NSArray *array3 = [NSArray arrayWithObjects:@"jack", @"rose", nil];
   9:      // [array2 count];
  10:      
  11:      //NSArray *array4 = [NSArray arrayWithObjects:@"jack", @"rose", @"4324324", nil];
  12:      
  13:      // 快速创建一个NSArray对象
  14:      NSArray *array4 = @[@"jack", @"rose", @"4324324"];
  15:      
  16:      
  17:      /*
  18:       2.NSArray的元素个数
  19:       */
  20:      NSLog(@"%ld", array3.count);
  21:      
  22:      
  23:      /*
  24:       3.NSArray中元素的访问
  25:       */
  26:      NSLog(@"%@", [array3 objectAtIndex:1]);
  27:      
  28:      //array3[1];
  29:      NSLog(@"%@", array3[0]);
posted @ 2015-03-06 18:24  有奈了  阅读(251)  评论(0编辑  收藏  举报