so I am looking for a regex which disallows two consecutive "." but it can have many. Also the string should not start or end with ".".
I've written a regex but it allows multiple dots consecutively.
new RegExp("^[0-9a-z].*[0-9a-z]$", "i"),
valid examples
"abc.def.hun.asasdsd"
"asasaasass.l"
"p.asasasas"
invalid examples
".asassa"
"sasas..sasas.sas"
"asas.sasas.sasas."
"sasas...sasasdsd.sasass"
You may use this regex:
/^[a-z\d](?!.*\.\.)(?:.*[a-z\d])?$/gmi
Explanation:
^[a-z\d]: Match alphanumeric char at start(?!.*\.\.): Negative lookahead to fail the match if 2 consecutive dots are present anywhere(?:.*[a-z\d])?: Match anything followed by alphanumeric char. Make this an optional group match$: EndYou can use this command, to start with ^[0-9a-z] with the number of letters, and then groups of dot with letters and numbers but not two sequential dots.
const result = new RegExp("^[0-9a-z]+?(\.[0-9a-z]+)*$", "i").test('one.dsfsdf.');
console.log(result)