Java正则表达式从字符串中删除匹配项

Question

我正在尝试找出如何从我的字符串中删除找到的匹配项。所以我的代码示例目前如下所示:

public void checkText() {
    String helper = "985, 913, 123, SomeotherText, MoreText, MoreText";
    Pattern pattern = Pattern.compile("\\b\\d{3}");
    Matcher matcher = pattern.matcher(helper);
    while (matcher.find()) {
        String newtext = "Number: " + matcher.group() + "\n"+ newtext;
        helper.replaceAll(matcher.group(),"");
    }
    newtext = newtext + "________________\n"+ helper;
    editText.setText(newtext);
}

所以我的输入字符串是:985, 913, 123, SomeotherText, MoreText, MoreText

运行代码后我想看到的是这样的:

Number: 985
Number: 913
Number: 123
________________________
SomeotherText, MoreText, MoreText

任何人都可以告诉我当前代码有什么问题吗？

Answer 1

您可以在代码中更新一些内容:

• 您应该将替换的返回设置为helper
• 如果仅替换为空字符串，则替换中的字符串将以 , , , 开头，并保留逗号和后面的空格
• 您可以初始化变量String newtext = "";

查看Java demo

您的代码可能如下所示:

String helper = "985, 913, 123, SomeotherText, MoreText, MoreText";
Pattern pattern = Pattern.compile("\\b\\d{3}");
Matcher matcher = pattern.matcher(helper);
String newtext = "";

while (matcher.find()) {
    newtext = "Number: " + matcher.group() + "\n"+ newtext;
    helper = helper.replaceAll(matcher.group() + ", ","");
}
newtext = newtext + "________________\n"+ helper;
System.out.println(newtext);

结果:

Number: 123
Number: 913
Number: 985
________________
SomeotherText, MoreText, MoreText