Question

以下是要求：一世。如果有第一个，中间个和最后一个，则只显示名字和姓氏 II。如果有第一个和最后一个，则显示第一个和最后一个 III。如果只有名字，则只显示

我有以下代码：

String fullName = "first middle last";
Scanner nameScanner = new Scanner(fullName);
nameScanner.findInLine(" ");
MatchResult result = nameScanner.match();
if(result.groupCount() > 2)
{   
System.out.println(result.group(1)+ " "+ result.group(3));
}
else
{
System.out.println(fullName);
}

当我尝试运行代码时，我得到了

Exception in thread "main" java.lang.IllegalStateException: No match result available
at java.util.Scanner.match(Unknown Source)
at com.assignment.RunAssignmentApp.main(RunAssignmentApp.java:48)

我做错了什么？

Answer 1

String内置split()。

String fullName = "first middle last";
String[] names = fullName.split(" ");

switch(names.length) {
    case 3: // The string had three tokens. Print the first and last one.
        System.out.println(names[0] + names[2]);
        break;
    case 2: // The string had two tokens. Print both.
        System.out.println(names[0] + names[1]);
        break;
    case 1: // The string had one tokens. Print it.
        System.out.println(names[0]);
        break;
    default: // The string had less than one or greater than 3 tokens.
        System.out.println("You either have no name or a very long name!");
}

Answer 2

扫描仪无法正常工作。你写这篇文章的方式，你最好根据空格将输入分成字符串数组：

public static void nameScanner() {
    String fullName = "first middle last";
    String[] names = fullName.split(" "); // split the string at the spaces
    if (names.length > 2) {
        System.out.println(names[0] + " " + names[2]); // arrays start at index 0, so names[0] is first name
    } else {
        System.out.println(fullName);
    }
}

当然，如果您正在从用户那里获取输入，那么您肯定希望添加一些错误检查和处理，以确保您不会超出阵列的界限。

Answer 3

尝试

nameScanner.findInLine("(\\w+) (\\w+) (\\w+)");

扫描仪的第一个，中间名，姓氏

3 个答案: