Answers for "regex alphanumeric"

regex to identify numeric and alphanumeric

"^[a-zA-Z0-9_]*$"

javascript regular expression for alphanumeric

/^[a-z0-9]+$/i

^         Start of string
[a-z0-9]  a or b or c or ... z or 0 or 1 or ... 9
+         one or more times (change to * to allow empty string)
$         end of string    
/i        case-insensitive

regex allow alphanumeric and special characters

/^[ A-Za-z0-9_@./#&+-]*$/

alphanumeric regex validation

validPattern = "^[a-zA-Z0-9]{10}$"; // alphanumeric exact 10 letters
this.projectForm = this.fb.group({
 ...
 CIG: [null, [Validators.required, Validators.pattern(this.validPattern)],

regex alphanumeric

/^\w+$/