Hashes the input string into a whole number.
- Use 
String.prototype.split()andArray.prototype.reduce()to create a hash of the input string, utilizing bit shifting. 
代码实现
const sdbm = str => {
  let arr = str.split('');
  return arr.reduce(
    (hashCode, currentVal) =>
      (hashCode =
        currentVal.charCodeAt(0) +
        (hashCode << 6) +
        (hashCode << 16) -
        hashCode),
    0
  );
};
sdbm('name'); // -3521204949
翻译自:https://www.30secondsofcode.org/js/s/hash-string-into-number