正则表达式用于删除十进制字符串中的零

Question

I need to remove zeros from decimal string eg: 007.004(100.007) should be transformed to 7.4(100.7)

I tried using a matcher based on the pattern "0+(\\d)":

Pattern p = Pattern.compile(regex);
Matcher m = null;
try {

    m = p.matcher(version);
    while (m.find()) {
        System.out.println("Group : " + m.group());
        System.out.println("Group 1 : " + m.group(1));
        version = version.replaceFirst(m.group(), m.group(1));
        System.out.println("Version: " + version);
    }

but this results in 7.4(10.7). Any thoughts on this ?

Answer 1

You need to do a replacement with this pattern:

(\\([^)]+\\))|0+

and this replacement string

\\1 

In other words, you need to capture all that is between parenthesis first and then looking for zeros. use the replaceAll method.

Answer 2

If you are trying to remove leading zeroes before a nonzero digit, then you can match such runs with this pattern: "(?<!\\\\d)0+(?=[1-9])" . That even uses a zero-length lookahead, as your tags suggest you might have wanted to do. It would be simpler to use than yours, too, because it doesn't match anything you want to keep:

Pattern p = Pattern.compile("(?<!\\d)0+(?=[1-9])");
Matcher m = p.matcher(version);;

version = matcher.replaceAll("");

If you're only going to do this once, then you can simplify to a one-liner:

version = version.replaceAll("(?<!\\d)0+(?=[1-9])", "");

Answer 3

There is no need to perform a replacement in another string while matching another:

while (m.find()) {
version = version.replaceFirst(m.group(), m.group(1));

You can instead use this replacement:

version = version.replaceAll("(^|\\.)0+", "$1");