Javascript code in SQL query in Mysql 9

[hrach]

https://dev.mysql.com/doc/refman/9.0/en/mysql-nutshell.html

CREATE FUNCTION gcd(a INT, b INT) 
RETURNS INT 
NO SQL 
LANGUAGE JAVASCRIPT AS
  $mle$
    let x = Math.abs(a)
    let y = Math.abs(b)
    while(y) {
      var t = y
      y = x % y
      x = t
    }
    return x
  $mle$
;