如何：使用 for each 循环访问数组

本主题演示如何对数组使用的不同类型的 for each，in 关键字。

示例

此示例演示如何对的数组 for each 引用类型。注意，如果一个维数组的所有维数多为零，for each 循环不循环访问数组。

// for_each_arrays.cpp
// compile with: /clr
using namespace System;
ref struct MyClass {
   void Test() { Console::WriteLine("in MyClass"); }
};

ref struct MyClass2 {
   void Test() { Console::WriteLine("in MyClass2"); }
};

int main() {
   array<MyClass ^> ^ MyArray = gcnew array<MyClass ^>(2);

   int i = 0;
   for each ( MyClass ^ c in MyArray ) {
      Console::Write("{0} = ", i++);
      c -> Test();
   }

   Console::WriteLine();

   array< MyClass2 ^, 2 > ^ MyArray2 = gcnew array< MyClass2 ^, 2 >(2, 2);
   i = 0;
   for each ( MyClass2 ^ c in MyArray2 ) {
      Console::Write("{0} = ", i++);
      c -> Test();
   }

   array< MyClass2 ^, 2 > ^ MyArray3 = gcnew array< MyClass2 ^, 2 >(2, 0);
   i = 0;
   for each ( MyClass2 ^ c in MyArray3 ) {
      Console::Write("{0} = ", i++);
      c -> Test();
   }
}

此示例将循环访问 ArrayList中的每种显示，请实现 IEnumerable。

// for_each_arrays_2.cpp
// compile with: /clr
using namespace System;
using namespace System::Collections;

int main() {
   int retval = 0;

   ArrayList ^ arr = gcnew ArrayList();
   arr->Add(10);
   arr->Add(20);
   arr->Add(30);
   
   for each ( int c in arr )
      retval += c;
   Console::WriteLine(retval);
}

此示例演示如何循环访问数组。

// for_each_arrays_3.cpp
// compile with: /clr
using namespace System;

#define ARRAY_SIZE 2

int main() {
   int i, j;

   // Declares an array of managed arrays of Int32.
   array< array< Int32 > ^ > ^ IntArray = gcnew array<array< Int32 > ^>(ARRAY_SIZE);

   for (i = 0 ; i < ARRAY_SIZE ; i++) {
      IntArray[i] = gcnew array< Int32 >(ARRAY_SIZE);
         for ( int j = 0 ; j < ARRAY_SIZE ; j++ ) 
            IntArray[i][j] = i + 10;
   }

   for (i = 0 ; i < ARRAY_SIZE ; i++)
      for (int j = 0 ; j < ARRAY_SIZE ; j++)
         Console::WriteLine("IntArray[{0}] = {1}", i, IntArray[i][j]);
   Console::WriteLine();

   for each (array<Int32> ^ xyz in IntArray)
      for each ( int c in xyz )
         Console::WriteLine(c);
}

请参见

参考

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