"为什么 a show "function getFullYear() { [native code for Date.getFullYear, arity=0] }" 而不是方法返回的值？"

Question

In the Google Apps Script Editor I have the following code

  function t(){
    var d = new Date;
    Logger.log(d);
    var y = d.getFullYear;
    Logger.log(y);
    if (y == 2013) {
      Logger.log("yes");
    } else {
      Logger.log("No");
    }
  }

Answer 1

This stores a reference to the getFullYear function in y :

var y = d.getFullYear;

This calls the getFullYear function and stores the result of the function call in y :

var y = d.getFullYear();
// ------------------^^

Perhaps you're confused because you can create objects with or without the parentheses (assuming you don't need to pass any arguments of course):

var d1 = new Date;
var d2 = new Date();

Both of those do the same thing but that's just a quirk/feature of the new operator.

Answer 2

var y = d.getFullYear; chanege var y = d.getFullYear(); your problems must solve with this way. you forgot that "()"