摘要:[VB6][VB.NET][C#][JAVA] 遞迴函數
遞迴(Recursive)
遞迴的優點：
1.增加程式的可讀性
2.可處理較複雜的問題
遞迴的缺點：
1.需花費較多的時間
2.利用暫存堆疊(Stack)的觀念，需要額外的儲存空間，效能比較差
VB6&VBA：
Option Explicit
Private Sub Command1_Click()
Private
If IsNumeric(Text1.Text) Then Text2.Text = f1(CInt(Text1.Text)) If IsNumeric(Text1.Text) Then Text3.Text = f2(CInt(Text1.Text))
End Sub'計算1乘到N的函數：
Private Function f1(ByVal n As Integer) As Double
Private Select Case n Case 1 f1 = 1 Case Else f1 = n * f1(n - 1) End SelectEnd Function'計算1加到N的函數：
Private Function f2(ByVal n As Integer) As Double Select Case n Case 1 f2 = 1 Case Else f2 = n + f2(n - 1) End Select
End FunctionVB.NET 2005：
Public Class Form1 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.ClickIf IsNumeric(TextBox1.Text) Then TextBox2.Text = f1(CInt(TextBox1.Text))
If IsNumeric(TextBox1.Text) Then TextBOX3.Text = f2(CInt(TextBox1.Text)) End Sub '計算1乘到N的函數： Private Function f1(ByVal n As Integer) As Double Select Case n Case 1 f1 = 1 Case Else f1 = n * f1(n - 1) End Select End Function '計算1加到N的函數： Private Function f2(ByVal n As Integer) As Double Select Case n Case 1 f2 = 1 Case Else f2 = n + f2(n - 1) End Select End FunctionEnd ClassJAVA：
private static double rfc(int g){ switch (g) { case 1: return 1; //break; default: return g * rfc(g - 1); }}C#：
using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Text;using System.Windows.Forms;namespace WindowsApplication1{ public partial class Form1 : Form { public Form1() { InitializeComponent(); }private void button1_Click(object sender, EventArgs e)
{ int n; if (int.TryParse(textBox1.Text, out n)) { //為數字 int va = Int32.Parse(textBox1.Text); textBox2.Text = System.Convert.ToString(rfc(va)); } else { MessageBox.Show ("請輸入數字"); } } private static double rfc(int g) { switch (g) { case 1: return 1; default: return g * rfc(g - 1); } } }}
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Microsoft MVP Award 2010~2017 C# 第四季
Microsoft MVP Award 2018~2022 .NET
