Android/Java Regex to remove extra zeros from sub-strings

Question

I have the following string as input :

\"2.0,3.00,-4.0,0.00,-0.00,0.03,2.01,0.001,-0.03,101\"

Final output will be like :

Answer 1

UPDATE to cover more cases such as 01.,.100, 01.10

(?<=,|^)(?:[0.+-]+(?=0(?:,|\.\B|$))|0+(?=[1-9]))|\.0+\b|\b0+(?=\d*\.\b)|\.\B|(?<=[1-9])0+(?=,|$)

This pattern requires more backtracking, thus can get slower on large input. Java String:

"(?<=,|^)(?:[0.+-]+(?=0(?:,|\\.\\B|$))|0+(?=[1-9]))|\\.0+\\b|\\b0+(?=\\d*\\.\\b)|\\.\\B|(?<=[1-9])0+(?=,|$)"

In addition to the previous pattern this one matches

• (?<=,|^)(?:...|0+(?=[1-9])) add leading zeros preceding [1-9]
• \.0+\b modified to match period with zeros only before a word boundary
• \b0+(?=\d*\.\b) match zeros at boundary if period preceded by optional digits ahead
• \.\B matches a period bordering to a non word boundary (eg .,)
• (?<=[1-9])0+(?=,|$) matches trailing zeros following [1-9]

Demo at regex101 or Regexplanet (click Java)

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^{Answer before update}
You can also try replaceAll this regex with empty.

(?<=,|^)[0.+-]+(?=0(?:,|$))|\.0+\b|\b0+(?=\.)

• (?<=,|^)[0.+-]+(?=0(?:,|$)) matches all parts that consist only of [0.+-] with at least a trailing zero. Limited by use of lookaround assertions: (?<=,|^) and (?=0(?:,|$))

• |\.0+\b or match a period followed by one or more zeros and a word boundary.

• |\b0+(?=\.) or match a boundary followed by one or more zeros if a period is ahead.

Unquestioned cases like 0.,01,1.10 are not covered by this pattern yet. As a Java String:

"(?<=,|^)[0.+-]+(?=0(?:,|$))|\\.0+\\b|\\b0+(?=\\.)"

Demo at regex101 or Regexplanet (click Java)