Name : is_empty(obj) - Language : JavaScript - type : function - platform : generic

is_empty.js

function is_empty(obj) {
  "use strict";
  // assign object type 
  var objType = Object.prototype.toString.call(obj);
  
  // is type === object 
  if (objType === '[object Object]') {
    // Assume if it has a length property with a non-zero value
    // that that property is correct.
    if (obj.length && obj.length > 0) { return false; }
    if (obj.length && obj.length === 0) {return true; }

    for (var key in obj) {
      if (Object.prototype.hasOwnProperty.call(obj, key)) { return false; }
    }
    
  // is type === array OR type === string
  } else if ( objType === '[object Array]' || objType === '[object String]' ) {
    
    if (obj.length && obj.length > 0) { return false; }
    
  }
  
  return true;
  
}

// Examples
console.log(
    is_empty(""), // True
    is_empty([]), // True
    is_empty({}), // True
    is_empty({length: 0, custom_property: []}), // True

    is_empty("Hello"), // False
    is_empty([1,2,3]), // False
    is_empty({test: 1}), // False
    is_empty({length: 3, custom_property: [1,2,3]}) // False
);