javascript - Restricting a user to enter more than 7 digits before decimel and 3 after decimel -

I have to get input from a user in a text box, but I have to validate it

1 It should not take more than 7 digits before decimals.

2. After the decimation it should not take more than 3 digits

I actually found 2 parts, but The first part is still a problem, my regular expression is:

  / ^ ([0-9] {0}} + (\ [0- 9] {1,3}) $ $    

Tell me where is wrong Is

suggest a legitimate regulatory expression

You do not need Plus , And I'll use \ d instead of [0- 9] , but I do not know that it's fast:

  / ^ \ D {0}} (\. \ D {1,3}) $$ /  

The reason your regex failed is that you have to do your first test There was a later + sign, which means "one or more matches" therefore it is going to search for more sets at [0- 9] {0} Was, which will match the characters in any number before the tenth spot.