【递归】递归的运用

递归遍历文件夹

另外如果用java代码删除目录应该从里往外删除，因为如果目录中有文件，那么目录删除不成功

package com.xiaozhi.helloio;import java.io.File;import java.io.FilenameFilter;public class Test3 {public static void main(String[] args) {ShowFile(new File("c:\\root"));}private static void ShowFile(File rootFile) {System.out.println(rootFile);File []files=rootFile.listFiles();for(File file: files){if(file.isDirectory()){ShowFile(file);}else {System.out.println(file);}}}}

递归求二进制

package com.xiaozhi.helloio;public class Test4 {public static void main(String[] args) {method(4);}public static void method( int num){System.out.println(num%2);if(num/2>0){method(num/2);}}}

递归求和

package com.xiaozhi.helloio;public class Test5 {public static void main(String[] args) {System.out.println(method(10000000));;}public static  int method(int num) {if(num >0)return num+method(num-1);return 0;}}