Objective-C 指针数组

在我们理解指针数组的概念之前，让我们看一下下面的实例，它使用了 3 个整数数组:

#import <Foundation/Foundation.h>
const int MAX = 3;
int main () {
  int var[] = {10, 100, 200};
  int i;
  for (i = 0; i < MAX; i++) {
   NSLog(@"Value of var[%d] = %d\n", i, var[i] );
  }
  return 0;
}

结果如下:

2022-07-07 00:22:57.136 demo[18206] Value of var[0] = 10
2022-07-07 00:22:57.136 demo[18206] Value of var[1] = 100
2022-07-07 00:22:57.136 demo[18206] Value of var[2] = 200

当我们想要维护一个数组时，可能会出现这样的情况，该数组可以存储指向 int 或 char 或任何其他可用数据类型的指针。下面是指向整数的指针数组的声明:

int *ptr[MAX];

这将 ptr 声明为 MAX 整数指针数组。因此，ptr 中的每个元素现在都有一个指向 int 值的指针。下面的示例使用 3 个整数，它们将存储在指针数组中，如下所示:

#import <Foundation/Foundation.h>
const int MAX = 3;
int main () {
  int var[] = {10, 100, 200};
  int i, *ptr[MAX];
  for ( i = 0; i < MAX; i++) {
   ptr[i] = &amp;var[i];  /* assign the address of integer. */
  }
  for ( i = 0; i < MAX; i++) {
   NSLog(@"Value of var[%d] = %d\n", i, *ptr[i] );
  }
  return 0;
}

结果如下:

2022-07-07 00:27:47.904 demo[3825] Value of var[0] = 10
2022-07-07 00:27:47.905 demo[3825] Value of var[1] = 100
2022-07-07 00:27:47.905 demo[3825] Value of var[2] = 200

您还可以使用指向字符的指针数组来存储字符串列表，如下所示:

#import <Foundation/Foundation.h>
const int MAX = 4;
int main () {
  char *names[] = {"Zara Ali", "Hina Ali", "Nuha Ali", "Sara Ali",};
  int i = 0;
  for ( i = 0; i < MAX; i++) {
   NSLog(@"Value of names[%d] = %s\n", i, names[i] );
  }
  return 0;
}

结果如下:

2022-07-07 00:30:25.438 demo[13476] Value of names[0] = Zara Ali
2022-07-07 00:30:25.439 demo[13476] Value of names[1] = Hina Ali
2022-07-07 00:30:25.439 demo[13476] Value of names[2] = Nuha Ali
2022-07-07 00:30:25.439 demo[13476] Value of names[3] = Sara Ali