Question

我正在尝试使用正则表达式在一行中找到我的模式的多个条目。注意：我一直在使用Regex大约一个小时...... = /

例如：

<a href="G2532" id="1">back</a> <a href="G2564" id="2">next</a>

应匹配两次：

1) <a href="G2532" id="1">back</a>
2) <a href="G2564" id="2">next</a>

我认为答案在于正确掌握贪婪与不情愿与占有欲，但我似乎无法让它发挥作用......

我认为我很接近，到目前为止我创建的正则表达式字符串是：

(<a href=").*(" id="1">).*(</a>)

但正则表达式匹配器返回1个匹配，整个字符串......

我在下面的代码中有一个（可编译的）Java正则表达式测试工具。这是我最近（徒劳）尝试使用该程序获得此功能，输出应该非常直观。

Enter your regex: (<a href=").*(" id="1">).*(</a>)
Enter input string to search: <a href="G2532" id="1">back</a> <a href="G2564" id="2">next</a>
I found the text "<a href="G2532" id="1">back</a> <a href="G2564" id="2">next</a>" starting at index 0 and ending at index 63.

Enter your regex: (<a href=").*(" id="1">).*(</a>)?
Enter input string to search: <a href="G2532" id="1">back</a> <a href="G2564" id="2">next</a>
I found the text "<a href="G2532" id="1">back</a> <a href="G2564" id="2">next</a>" starting at index 0 and ending at index 63.

Enter your regex: (<a href=").*(" id="1">).*(</a>)+
Enter input string to search: <a href="G2532" id="1">back</a> <a href="G2564" id="2">next</a>
I found the text "<a href="G2532" id="1">back</a> <a href="G2564" id="2">next</a>" starting at index 0 and ending at index 63.

Enter your regex: (<a href=").*(" id="1">).*(</a>)?
Enter input string to search: <a href="G2532" id="1">back</a> <a href="G2564" id="2">next</a>
I found the text "<a href="G2532" id="1">back</a> <a href="G2564" id="2">next</a>" starting at index 0 and ending at index 63.

Enter your regex: ((<a href=").*(" id="1">).*(</a>))?
Enter input string to search: <a href="G2532" id="1">back</a> <a href="G2564" id="2">next</a>
I found the text "<a href="G2532" id="1">back</a> <a href="G2564" id="2">next</a>" starting at index 0 and ending at index 63.
I found the text "" starting at index 63 and ending at index 63.

Enter your regex: ((<a href=").*(" id="1">).*(</a>))+?
Enter input string to search: <a href="G2532" id="1">back</a> <a href="G2564" id="2">next</a>
I found the text "<a href="G2532" id="1">back</a> <a href="G2564" id="2">next</a>" starting at index 0 and ending at index 63.

Enter your regex: (((<a href=").*(" id="1">).*(</a>))+?)
Enter input string to search: <a href="G2532" id="1">back</a> <a href="G2564" id="2">next</a>
I found the text "<a href="G2532" id="1">back</a> <a href="G2564" id="2">next</a>" starting at index 0 and ending at index 63.

这是Java：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.regex.Pattern;
import java.util.regex.Matcher;

public class RegexTestHarness {

    public static void main(String[] args){
        try{
            while (true) {

                System.out.print("\nEnter your regex: ");

                BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
                Pattern pattern = Pattern.compile(reader.readLine());

                System.out.print("Enter input string to search: ");
                Matcher matcher = pattern.matcher(reader.readLine());

                boolean found = false;
                while (matcher.find()) {
                    System.out.println("I found the text \"" + matcher.group() + "\" starting at " +
                       "index " + matcher.start() + " and ending at index " + matcher.end() + ".");
                    found = true;
                }
                if(!found){
                    System.out.println("No match found.");
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
            System.exit(-1);
        }

    }
}

Answer 1

试试这个：

<a href=".*?" id="1">.*?</a>

我已在?

之后添加.*，将捕获转换为非贪婪

但是如果有疑问，你可以使用这个技巧：

<a href="[^"]*" id="1">[^<]*</a>

[^"]*表示不是双引号的任意数量的字符 [^<]*表示任意数量的不是左角的字符

所以你要避免担心贪婪/非贪婪

我需要帮助让Regex表达正确

1 个答案: