String validation with regex in JS

Question

I need a help to frame a regex to validate a string format in Javascript,

Total length of the string should be between 3 and 30 characters length. First character must be strictly an alphabet. Subsequent characters can be either alphabet or dot or space. Please help.

Answer 1

The following will work for you.

var re = /^[a-z][a-z. ]{2,29}$/i

Regular expression:

^                # the beginning of the string
 [a-z]           # any character of: 'a' to 'z'
 [a-z. ]{2,29}   # any character of: 'a' to 'z', '.', ' ' (between 2 and 29 times)
$                # before an optional \n, and the end of the string