Regex that only matches when 4 specific words were found-CodePudding

As the title says, I need a Regex to check if a string has this four words (Update, Rollback, Skip, Not Now) and only return them if all of them are present, if not it doesn’t return anything.

Here is an example: {"Update":"iVBORw0KGgo","Rollback":"iVBORw0KGgo","Skip":"iVBORw0KGgo","Not Now":"iVBORw0KGgo"}

In this case, it should return [Update, Rollback, Skip, Not Now]

{"Update":"iVBORw0KGgo","Skip":"iVBORw0KGgo","Not Now":"iVBORw0KGgo"}

In this case, it shouldn’t return any value

I tried to create one by myself but my knowledge of Regex is very basic: (Update|Rollback|Skip|Not Now)

Thanks in advance!

CodePudding user response：

As an alternative to regex, you can use JSON.parse to parse the string into an object and Object.keys to get the properties:

const str = `{"Update":"iVBORw0KGgo","Rollback":"iVBORw0KGgo","Skip":"iVBORw0KGgo","Not Now":"iVBORw0KGgo"}`;

const keys = Object.keys(JSON.parse(str))

const result = keys.sort().toString() == "Not Now,Rollback,Skip,Update" ? keys : "";

console.log(result)

CodePudding user response：

While regex is clearly not a good tool for the job, you can do something like this:

re.match("(?=.*Update.*)(?=.*Skip.*)",string)

"(?=WORD)" matches if the expression follows, but doesn't consume any of the string.

Of course, complete the regex by all 4 words that you want similarly.

Also notice that regex by itself doesn't return anything. You need to code for this.

CodePudding user response：

Use this:

^(?=.*Update)(?=.*Rollback)(?=.*Skip)(?=.*Not Now).*$

(?=...) means that if you lookahead, you find this pattern.

So if we find all these 4 pattern, we accept the result.

demo