check for empty values in JavaScript for datatypes like Array, Object, String and Number

Question

I need to check whether enter parameter is empty or not like php empty function works.

For example, if I have function with name isEmpty and I passed string as parameter to it then function will return true if string is empty else false and similar for other datatypes like Object, Array and Number.

Answer 1

let isEmpty = param => {
	let isAnObject = (obj) => {
		if (obj == null) return false;
		return obj.constructor.name.toLowerCase() === "object"
	}
	if (Array.isArray(param)) {
		return !param.length;
	}
	if (isAnObject(param)) {
		return !Object.keys(param).length;
	}
	return !param;
}
console.log('Is empty Array: ',isEmpty([]));
console.log('Is empty Array: ',isEmpty([1,2,3]));
console.log('Is empty Object: ',isEmpty({}));
console.log('Is empty Object: ',isEmpty({a: 'I am not empty'}));
console.log('Is empty String: ',isEmpty(''));
console.log('Is empty String: ',isEmpty('I am string'));
console.log('Is empty Number: ',isEmpty(NaN));
console.log('Is empty Number: ',isEmpty(100));
console.log('Is empty String parse as number: ',isEmpty(parseInt('')));

I have created a function and named it as isEmpty. This function will return true if passed parameter is empty else false.