Question

我有一个String数组

String[] arrayOfLine = {
    "I.2 Other Interpretive Provisions",
    "I.3 Accounting Terms",
    "Including all",
    "II.1 The Loans",
    "II.3 Prepayments.",
    "III.2 Illegality",
    "IV.2 Conditions",
    "V.2 Authorization",
    "expected to have"
};

我想只选择那些以roman.number开头的数组元素从I.2，II.1等开始。

我正在尝试这个，但它无法正常工作

String regex = "\b[A-Z]+\\.[0-9]\b";
for (int i = 0; i < arrayOfLine.length; i++) {
    if(arrayOfLine[i].matches(regex)){
        listOfHeadings.add(arrayOfLine[i]);
    }
}

Answer 1

看起来您需要查找以该模式开头的所有项目。使用"^[A-Z]+\\.[0-9]+\\b"模式并确保运行find()对象的Matcher方法，以在字符串内找到部分匹配项。 .matches()仅查找整个字符串匹配项。请注意，\b字边界必须在Java字符串文字中定义为"\\b"。

请参阅Java demo

String[] arrayOfLine = {"I.2 Other Interpretive Provisions" , "I.3 Accounting Terms","Including all","II.1 The Loans","II.3 Prepayments.","III.2 Illegality","IV.2 Conditions","V.2 Authorization","expected to have"};
Pattern pat = Pattern.compile("^[A-Z]+\\.[0-9]+\\b");
List<String> listOfHeadings = new ArrayList<>();
for (String s : arrayOfLine) {
    Matcher m = pat.matcher(s);
    if (m.find()) {
        listOfHeadings.add(s);
    }
}
System.out.println(listOfHeadings);

Answer 2

您可以尝试使用Patterns和Matchers。这是一个工作示例

    Pattern pattern = Pattern.compile("[A-Z]+\\.[0-9]");
    for (int i = 0; i < arrayOfLine.length; i++) {
        Matcher match = pattern.matcher(arrayOfLine[i]);
        while (match.find()) {
            listOfHeadings.add(match.group());
        }
    }

Answer 3

此处regex用于检查罗马数字，其中点为^M{0,4}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})[.]。

import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
class test
    {
     public static void main(String[] args) {
     String[] a = {
     "I.2 Other Interpretive Provisions",
     "I.3 Accounting Terms",
     "Including all",
     "II.1 The Loans",
     "II.3 Prepayments.",
     "III.2 Illegality",
     "IV.2 Conditions",
     "V.2 Authorization",
     "expected to have"
     };
     int i=0;
     int b=a.length;
     Pattern MY_PATTERN = Pattern.compile("^M{0,4}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})[.]");
     for(i=0;i<b;i++)
     {
         Matcher m = MY_PATTERN.matcher(a[i]);
         if (m.find())
             System.out.println(a[i]);
     }
     }
 }

输出：

I.2 Other Interpretive Provisions
I.3 Accounting Terms
II.1 The Loans
II.3 Prepayments.
III.2 Illegality
IV.2 Conditions
V.2 Authorization

如何在java中使用带有String.matches的正则表达式

3 个答案: