Doubt with Javascript Replace


My situation : I have an input masked like this: 0,0000 % . However, to be able to validate as I want, I need to use a replace , changing the comma to the period, removing the % and then treating the value like this: 0.0000 .

I know I can use something like numero.replace(",",".") but that will only replace the comma with the period, and my validation will keep failing.

Is it possible in a single replace or similar code, change the characters and remove the % ?

Although the problem has already been solved, below is my answer to Sergio :

In my validation, I can only have numbers less than or equal to 100. As for the format (string or number), I cannot say with 100% certainty. I think it will have to be number , as this value will probably be stored in a BD and as a string I don't think it will be very viable.

Detail : It is not recommended that I use anything backend for now. Front-end only . It's more of a client side validation to not let the user send out bizarre values ​​in the post.


It is possible with regular expression. I'm not a master at the subject, but this seems to do the trick:

var re = /^(\d+),(\d+) %$/;
console.log("0,0000 %".replace(re, "$1.$2"));

The regular expression above works like this:

  • ^ : from the beginning of the string
  • (\d+) : there must be one or more digits; the parentheses are to capture what to match that part of the expression
  • , : followed by a comma
  • (\d+) : followed by one or more digits (again captured)
  • % : followed by space and percent sign
  • $ : end of string (ie nothing after percentage)

In the second part of replace , the two groups captured with parentheses are referenced as $1 and $2 respectively. That is, $1 is the digits before the comma, and $2 is the digits after it. We assemble a new string with these two terms, and . in the middle instead of , .

Considering your edit, this expression seems insufficient, as it allows for any number, even greater than 100 (except negatives, which you didn't mention but I'm considering invalid). A more precise expression:

/^(\d{1,2}|100),(\d+) %$/

The new part, (\d{1,2}|100) , means that before the comma there must be any two digits, or the value "100" .

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