排队。C# 中的 CopyTo()方法
原文:https://www . geeksforgeeks . org/queue-copy to-method-in-c-sharp/
此方法用于将队列元素复制到现有的一维数组中，从指定的数组索引开始。元素被复制到数组中的顺序与枚举器遍历队列的顺序相同，这个方法是一个 O(n)操作，其中 n 是 Count。该方法属于System.Collections命名空间。
语法:
public virtual void CopyTo (Array array, int index);
参数:
数组:一维数组是从 Queue 复制的元素的目的地。数组必须具有从零开始的索引。
索引:是数组中从零开始复制的索引。
异常:
- 参数空异常:如果数组为空。
- argumentoutofrangerexception:如果指数小于零。
- 参数异常:如果数组是多维的
Or源队列中的元素数量大于目标数组可以包含的元素数量。 - InvalidCastException: 如果源队列的类型无法自动转换为目标数组的类型。
以下程序说明了上述方法的使用:
例 1:
// C# code to illustrate the
// Queue.CopyTo(Array, Int32)
// Method
using System;
using System.Collections;
class GFG {
// Driver code
public static void Main()
{
// Creating an Queue
Queue myq = new Queue();
// Adding elements to Queue
myq.Enqueue("A");
myq.Enqueue("B");
myq.Enqueue("C");
myq.Enqueue("D");
// Creates and initializes the
// one-dimensional target Array.
String[] arr = new String[6];
// adding elements to Array
arr[0] = "HTML";
arr[1] = "PHP";
arr[2] = "Java";
arr[3] = "Python";
arr[4] = "C#";
arr[5] = "OS";
Console.WriteLine("Before Method: ");
Console.WriteLine("\nQueue Contains: ");
// Displaying the elements in myq
foreach(Object obj in myq)
{
Console.WriteLine(obj);
}
Console.WriteLine("\nArray Contains: ");
// Displaying the elements in arr
for (int i = 0; i < arr.Length; i++) {
Console.WriteLine("arr[{0}] : {1}", i, arr[i]);
}
Console.WriteLine("After Method: ");
// Copying the entire source Queue
// to the target Array starting at
// index 2.
myq.CopyTo(arr, 2);
Console.WriteLine("\nQueue Contains: ");
// Displaying the elements in myq
foreach(Object obj in myq)
{
Console.WriteLine(obj);
}
Console.WriteLine("\nArray Contains: ");
// Displaying the elements in arr
for (int i = 0; i < arr.Length; i++) {
Console.WriteLine("arr[{0}] : {1}", i, arr[i]);
}
}
}
输出:
Before Method:
Queue Contains:
A
B
C
D
Array Contains:
arr[0] : HTML
arr[1] : PHP
arr[2] : Java
arr[3] : Python
arr[4] : C#
arr[5] : OS
After Method:
Queue Contains:
A
B
C
D
Array Contains:
arr[0] : HTML
arr[1] : PHP
arr[2] : A
arr[3] : B
arr[4] : C
arr[5] : D
例 2:
// C# code to illustrate the
// Queue.CopyTo(Array, Int32)
// Method
using System;
using System.Collections;
class GFG {
// Driver code
public static void Main()
{
// Creating an Queue
Queue myq = new Queue();
// Adding elements to Queue
myq.Enqueue("A");
myq.Enqueue("B");
myq.Enqueue("C");
myq.Enqueue("D");
// Creates and initializes the
// one-dimensional target Array.
String[] arr = new String[2];
// adding elements to Array
arr[0] = "HTML";
arr[1] = "PHP";
arr[2] = "Java";
arr[3] = "Python";
arr[4] = "C#";
arr[5] = "OS";
Console.WriteLine("Before Method: ");
Console.WriteLine("\nQueue Contains: ");
// Displaying the elements in myq
foreach(Object obj in myq)
{
Console.WriteLine(obj);
}
Console.WriteLine("\nArray Contains: ");
// Displaying the elements in arr
for (int i = 0; i < arr.Length; i++) {
Console.WriteLine("arr[{0}] : {1}", i, arr[i]);
}
Console.WriteLine("After Method: ");
// using Method but It will give
// Runtime Error as number of elements
// in the source Queue is greater
// than the number of elements that
// the destination array can contain
myq.CopyTo(arr, 2);
Console.WriteLine("\nQueue Contains: ");
// Displaying the elements in myq
foreach(Object obj in myq)
{
Console.WriteLine(obj);
}
Console.WriteLine("\nArray Contains: ");
// Displaying the elements in arr
for (int i = 0; i < arr.Length; i++) {
Console.WriteLine("arr[{0}] : {1}", i, arr[i]);
}
}
}
运行时错误:
未处理异常: 系统。IndexOutOfRangeException:索引超出了数组的界限。 at(包装中柱)系统。Object.virt _ 石碑 ref_sealed_class(intptr，Object)
参考:
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