Javascript Null and Empty check

Question

export const notEmpty = (data) => {
  const type = Object.prototype.toString.call(data).slice(8, -1).toLowerCase();
  switch (type) {
    case 'null':
    case 'undefined':
      return false;
    case 'object':
      return Object.keys(data).length > 0;
    case 'array':
    case 'string':
      return data !== 'undefined' && data !== 'null' && data.length > 0;
    case 'boolean':
      return !!data;
    default:
      return true;
  }
};

I've made above function for checking null, undefined, '' and empty Array and Object. But as you can see, it has many ifs. Is there another better solution for checking them?

technophyle · Accepted Answer · 2020-05-14 17:20:27Z

2

Your current function doesn't look bad, but you can improve it like this:

const notEmpty = (data) => {
  if (!data) return false;
  
  if (typeof data === 'object') return Object.keys(data).length > 0;

  return true;
};

console.log(notEmpty(null));
console.log(notEmpty(undefined));
console.log(notEmpty(''));
console.log(notEmpty({}));
console.log(notEmpty([]));
console.log(notEmpty(false));

console.log(notEmpty({ a: 1 }));
console.log(notEmpty(true));
console.log(notEmpty('abc'));
console.log(notEmpty([1, 2, 3]));

Arrays are objects, so the above will check for arrays as well.

edited May 14, 2020 at 17:20

answered May 13, 2020 at 16:46

technophyle

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3 Comments

Christian Vincenzo Traina Over a year ago

case 'string' is actually useless, empty strings are falsy :)

epascarello Over a year ago

Edge case if it is a number notEmpty(0) (which was not in the orginal)

technophyle Over a year ago

yeah, that was not in the original method and since he is returning false for false boolean value, it probably means he wants false for 0 as well, I'm not sure.

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