javascript - Should one write window.X when referring to a built-in global property X in the (desktop) browser? -

Therefore, (desktop) browsers have dozens of built-in global properties, for example:

• document
• undefined
• parseInt
• JSON
• Location
• Warning
• setTimout
• etc.

  While referring to those qualities, they should clearly note them as global property by prefixing them with their properties window. ? Therefore, for example:

    var wrap = window.document.getElementById ('wrap');   
   and  
    window.setTimeout (loop, 100);   
   and  
    var x = window.parseInt (input.value, 10);   
   I think there are three answers to this question:  
   
   
   Yes, you always write  window.X    
   
   No, you do not have to write  window.X . Just  X  is OK.   
   
   For some properties it depends on the property, use  window.X , for some other properties,  X  (If this is your answer, expand it.)    
   So, what is it?   
   
   
   I leave a few exceptions and go to 3: No  window .  
   In the browser, the  window  refers to the global scope  window.  As unnecessary in  window.prompt () , you can emphasize it to use that  prompt ()  a  window  is a method of object.  
   I will never use anything like  window math  or  window.NaN  because these properties are global objects that have  windows < There is nothing with the code / object which is a global object in the browser, also see.  
   If you have another variable in the existing (local) area of ​​the name  prompt , you will need the  window.  Initially as prefix:  
    (function () {var prompt = "Give me your name!" Var name = window.prompt (prompt, "your name") ;}));   
   For the setting of global variables, you should add the  window. To satisfy the equipment as a prefix (Otherwise, you might have forgotten  var  and accidentally leak a variable in the global scope):  
    (function () {// "wrong" somevar = 1; // You probably want to set a local variable, so should use: var somevar = 1; // remove confusion , You really want to set global variables: window.somevar = 1;}) ();   
   Generally, except the  window  By considering the next example, readability improvements:  
    window.setInterval (function () {var NumA = window.parseInt (window.document.getElementById ("numA"). Value, 10); var numb = window.parseInt (window.document.getElementById ("numB"). Value, 10); window.document.getElementById ("average"). Value = window.Math.floor ((numA + NumB) / 2);}, 1000);