olark javascript

olark.js

// Original snippet

function inspectObject(object) {
    for (key in object) {
        console.log("the attribute " + key + " is equal to " + object[key]);
    }
}

var widget = new Widget();
inspectObject(widget);


// Possible problems 

1. key is overwritten if already defined.

   To fix this change the loop to: for (var key in object)

   However, since JS is function scoped the key will be scoped for the whole inspectObject().
   Crockford says rather than write concise code that we should write what JS actually is doing, and so I'll put 'var key' on its own line.

   var key;
   for (key in object) {

2. for-in will iterate over properties further up the prototype chain. 

   To fix this add test for object.hasOwnProperty(key), if you only want the object's properties. 

   function inspectObject(object) {
     for (key in object) {
       if (object.hasOwnProperty(key)) {
         console.log("the attribute " + key + " is equal to " + object[key]);
       }
     }
   }

3. inspectObject() might be overwritten if already defined.

   To fix this add an anonymous function wrapper inside the script block.


The final script might look like:

(function () {
  function inspectObject(object) {
    var key;
    for (key in object) {
      if (object.hasOwnProperty(key)) {
        console.log("the attribute " + key + " is equal to " + object[key]);
      }
    }
  }

var widget = new Widget();
inspectObject(widget);
})();