Regular expression validation for telephone number

Question

I am using the following regex for telephone number validation. It is allowing all the cases except one.
^(\\+?\\ *[0-9]+)([0-9 ]*)([0-9 ])*$|(^ *$)

The conditions are
1. Allow numeric values
2. Allow plus sign only in the beginning

The regex is getting failed while I enter the first character as plus sign. If I have entered a number after the plus sign it will work. My requirement is the form should valid while entering the plus sign as the first character. I am using a Angular reactive form. So error will fire entreating the first character itself.

Thanks in advance.

Answer 1

Try this ^(\\+?)([0-9 ]*)([0-9 ])*$|(^ *$) .

But what you had initially is also fine but as you said its not your requirement, try the above one