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]);