將參數附加到字符串

Question

我需要編寫一個簡單的Java程序，以便遍歷給定的字符串（從args []給出），並在遇到某個字符（例如'^'）時接收println：

public class JavaApplication15 { 

    public static void main(String[] args) { 
     StringBuffer copyFromMe = null; 
     for (int j = args.length; --j<=0;) { 
      copyFromMe = new StringBuffer(); 
      copyFromMe.append(args[j]); 
     } 

     StringBuffer copyToMe = new StringBuffer(); 

     int i = 0; 
     char c = copyFromMe.charAt(i); 
     while (c != 'g') { 
      copyToMe.append(c); 
      c = copyFromMe.charAt(++i); 
     } 
     System.out.println(copyToMe); 
    } 

    private static String String(String[] args) { 
     throw new UnsupportedOperationException("Not supported yet."); 
    } 
} 

Answer 1

您正在爲循環的每次迭代創建new StringBuffer。您應該使用StringBuilder。你需要從args.length - 1開始。最後>= 0 like，

StringBuilder copyFromMe = new StringBuilder(); 
for (int j = args.length - 1; j>=0; j--) { 
    // copyFromMe = new StringBuffer(); 
    copyFromMe.append(args[j]); 
}