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javascriptjsonregexdust.js

Regex remove json property

I'd like to remove a stringfied json's property based on its key wherever it is, whatever its value type is. But removing it only if its value is a string and its on the root level of the object would be nice for a beggining. I tried this:

[,]{1}[\s]*?\"attrName\"[ ]*?[:][ ]*?\".*\"[^,]|\"attrName\"[ ]*?[:][ ]*?\".*\"[,]{0,1}

Example : https://regex101.com/r/PAlqYi/1

but it looks a lot big to do such a simple job, what it does is ensure the comma will be removed as well, if attrName is the first attribute, the last ot something in the middle of the json three. Does anyone has a better idea to make this regex more readable?

Solution

  • If you have any way of using a parser it's a more stable and readable solution. The regex \s*\"attr\" *: *\".*\"(,|(?=\s*\})) should be shorter and better.

    Example

    Several changes I made to help:

    1. Don't use so many character classes like [,]. If there is only one element in a character class it should be left by itself.
    2. Only use numbered counts when required. Ex: {0,1} is ? and {1} is pointless.
    3. Instead of searching for a comma in the previous line to see if it is the end of a list checking if there is a } following the line allows you to group the conditionals together.
    4. A positive lookahead is used at the end to search for } so it wouldn't be removed during the substitution.

    Update with bugfix mentioned in comments. Trailing commas would be left if the attribute is last. The simplest way I found to fix this was to match both cases. So, you'll have to fill in attr twice.

    (,\s*\"attr\" *: *\".*\"|(?=\s*\}))|(\s*\"attr\" *: *\".*\"(,|(?=\s*\})))

    Examples with added tests cases