生成反向話

Question

我在java的初學者，我在做什麼practiceit問題關閉internet.I試圖嘗試的問題，但我不明白的錯誤。

編寫一個名爲processName的方法，該方法接受控制檯的掃描儀作爲參數，並提示用戶輸入其全名，然後以相反順序（即姓氏，名字）打印名稱。你可能會認爲只會給出第一個和最後一個名字。你應該用掃描儀讀取輸入的整條生產線一次，然後根據需要打破它分開。下面是與用戶的樣本對話：

請輸入您的全名：薩米Jankis 你按相反的順序名字是Jankis，薩米

public static void processName(Scanner console) { 
    System.out.print("Please enter your full name: "); 

    String full=console.nextLine(); 

    String first=full.substring(0," "); 
    String second=full.substring(" "); 

    System.out.print("Your name in reverse order is: "+ second + "," + first); 

} 

也許我會去解釋我的code.So我嘗試打破這兩個詞apart.So我使用的串找到這兩個詞，然後我硬編碼扭轉他們。我認爲邏輯是正確的，但我仍然得到這些錯誤。

Line 6 
You are referring to an identifer (a name of a variable, class, method, etc.) that is not recognized. Perhaps you misspelled it, mis-capitalized it, or forgot to declare it? 
cannot find symbol 
symbol : method substring(int,java.lang.String) 
location: class java.lang.String 
    String first=full.substring(0," "); 
        ^
Line 7 
You are referring to an identifer (a name of a variable, class, method, etc.) that is not recognized. Perhaps you misspelled it, mis-capitalized it, or forgot to declare it? 
cannot find symbol 
symbol : method substring(java.lang.String) 
location: class java.lang.String 
    String second=full.substring(" "); 
        ^
2 errors 
33 warnings 

Answer 1

public static void processName(Scanner console) { 
    System.out.print("Please enter your full name: "); 

    String[] name = console.nextLine().split("\\s"); 

    System.out.print("Your name in reverse order is: "+ name[1] + "," + name[0]); 

} 

當然，如果名下有2個字它纔會起作用。對於較長的名字，你應該寫這將扭轉數組

Answer 2

按Java API，substring()接受像substring(int beginIndex)和兩個int參數，像substring(int startIndex, int endIndex)任何一個int參數，但你用字符串參數調用一個方法。所以你會得到這些錯誤。更多信息可以在這裏 String API找到。

Answer 3

看看爲substring()方法的文檔。它不會將字符串作爲其第二個參數。

String first=full.substring(0," "); 
    String second=full.substring(" "); 

你可能想要的是indexOf()方法。首先找到空格字符的索引。然後找到到那個點的子串。

int n = full.indexOf(" "); 
    String first=full.substring(o, n); //gives the first name 

Answer 4

回到這裏http://docs.oracle.com/javase/6/docs/api/java/lang/String.html並閱讀了解。

Answer 5

public class ex3_11_padString { 
    public static void main(String[] args) { 
     System.out.print("Please enter your full name: "); 
     String f_l_Name = console.nextLine(); 
     String sss[] = f_l_Name.split(" ", 2); 
     System.out.print("Your name in reverse order is " + sss[1] + ", " + sss[0]); 
    } 
}