生成反向话

Question

我在java的初学者，我在做什么practiceit问题关闭internet.I试图尝试的问题，但我不明白的错误。

编写一个名为processName的方法，该方法接受控制台的扫描仪作为参数，并提示用户输入其全名，然后以相反顺序（即姓氏，名字）打印名称。你可能会认为只会给出第一个和最后一个名字。你应该用扫描仪读取输入的整条生产线一次，然后根据需要打破它分开。下面是与用户的样本对话：

请输入您的全名：萨米Jankis 你按相反的顺序名字是Jankis，萨米

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); 

} 

也许我会去解释我的code.So我尝试打破这两个词apart.So我使用的串找到这两个词，然后我硬编码扭转他们。我认为逻辑是正确的，但我仍然得到这些错误。

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]); 

} 

当然，如果名下有2个字它才会起作用。对于较长的名字，你应该写这将扭转数组

Answer 2

按Java API，substring()接受像substring(int beginIndex)和两个int参数，像substring(int startIndex, int endIndex)任何一个int参数，但你用字符串参数调用一个方法。所以你会得到这些错误。更多信息可以在这里 String API找到。

Answer 3

看看为substring()方法的文档。它不会将字符串作为其第二个参数。

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。然后找到到那个点的子串。

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

Answer 4

回到这里http://docs.oracle.com/javase/6/docs/api/java/lang/String.html并阅读了解。

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]); 
    } 
}