goto (C# 參考使用

goto (C# 參考)

goto 陳述式將程式控制直接轉移到標記陳述式。

 備註

goto 的常見用法是轉移控制至特定的 switch-case 標記或 switch 陳述式中預設的標記。

goto 陳述式對於跳出複雜的巢狀迴圈也很有用。

 範例

下列範例說明在 switch 陳述式中使用 goto。

複製程式碼

// statements_goto_switch.cs
using System;
class SwitchTest
{
static void Main()
{
Console.WriteLine("Coffee sizes: 1=Small 2=Medium 3=Large");
Console.Write("Please enter your selection: ");
string s = Console.ReadLine();
int n = int.Parse(s);
int cost = 0;
switch (n)
{
case 1:
cost += 25;
break;
case 2:
cost += 25;
goto case 1;
case 3:
cost += 50;
goto case 1;
default:
Console.WriteLine("Invalid selection.");
break;
}
if (cost != 0)
{
Console.WriteLine("Please insert {0} cents.", cost);
}
Console.WriteLine("Thank you for your business.");
}
}

輸入

2

範例輸出

Coffee sizes: 1=Small 2=Medium 3=Large
Please enter your selection: 2
Please insert 50 cents.
Thank you for your business.

以下的範例說明使用 goto 以中斷巢狀迴圈。

複製程式碼

// statements_goto.cs
// Nested search loops
using System;
public class GotoTest1
{
static void Main()
{
int x = 200, y = 4;
int count = 0;
string[,] array = new string[x, y];
// Initialize the array:
for (int i = 0; i < x; i++)
for (int j = 0; j < y; j++)
array[i, j] = (++count).ToString();
// Read input:
Console.Write("Enter the number to search for: ");
// Input a string:
string myNumber = Console.ReadLine();
// Search:
for (int i = 0; i < x; i++)
{
for (int j = 0; j < y; j++)
{
if (array[i, j].Equals(myNumber))
{
goto Found;
}
}
}
Console.WriteLine("The number {0} was not found.", myNumber);
goto Finish;
Found:
Console.WriteLine("The number {0} is found.", myNumber);
Finish:
Console.WriteLine("End of search.");
}
}