Asked  7 Months ago    Answers:  5   Viewed   41 times

Seems like the following code should return a true, but it returns false.

var a = {};
var b = {};

console.log(a==b); //returns false
console.log(a===b); //returns false

How does this make sense?

 Answers

20

The only difference between regular (==) and strict (===) equality is that the strict equality operator disables type conversion. Since you're already comparing two variables of the same type, the kind of equality operator you use doesn't matter.

Regardless of whether you use regular or strict equality, object comparisons only evaluate to true if you compare the same exact object.

That is, given var a = {}, b = a, c = {};, a == a, a == b, but a != c.

Two different objects (even if they both have zero or the same exact properties) will never compare equally. If you need to compare the equality of two object's properties, this question has very helpful answers.

Tuesday, June 1, 2021
 
hakimoun
answered 7 Months ago
37

You almost got there. As you already got sel1's value, the rest is to filter options for sel1 based on the value.

var sel1 = document.querySelector('#sel1');
var sel2 = document.querySelector('#sel2');
var options2 = sel2.querySelectorAll('option');

function giveSelection(selValue) {
  sel2.innerHTML = '';
  for(var i = 0; i < options2.length; i++) {
    if(options2[i].dataset.option === selValue) {
      sel2.appendChild(options2[i]);
    }
  }
}

giveSelection(sel1.value);
<select id="sel1" onchange="giveSelection(this.value)">
  <option value="a">a</option>
  <option value="b">b</option>
</select>
<select id="sel2">
  <option data-option="a">apple</option>
  <option data-option="a">airplane</option>
  <option data-option="b">banana</option>
  <option data-option="b">book</option>
</select>
Thursday, July 29, 2021
 
Fernando
answered 5 Months ago
46

== compares references, .equals() compares values. These two Longs are objects, therefore object references are compared when using == operator.

However, note that in Long id1 = 123L; literal value 123L will be auto-boxed into a Long object using Long.valueOf(String), and internally, this process will use a LongCache which has a [-128,127] range, and 123 is in this range, which means, that the long object is cached, and these two are actually the same objects.

Tuesday, August 3, 2021
 
giraffeslacks
answered 4 Months ago
69

I was able to fix this issue by making browser sleep for few seconds after every change in URL.

Below is the code snippet:

67 it('should create new job listing', function () {
68        //Login As Admin To Access Vacancies Feature
69        loginAsManager();
.
.        //load manager's dashboard list page
.        dashboardPage = new DashboardPage();
.        dashboardPage.vacanciesTab.click();
.
.        //load vacancies list page
.        var vacanciesUrl = browser.baseUrl + '#/vacancies';
.        browser.sleep(2000);
.        expect(browser.getCurrentUrl()).toEqual(vacanciesUrl);
.        vacanciesPage = new VacanciesPage();
.        vacanciesPage.addVacancyButton.click();
.
.

I don't think this is a neat solution to this problem.

I will be happy to hear, if someone has a better solution to this.

Cheers Gaurav

Friday, October 15, 2021
 
Morrison Chang
answered 2 Months ago
94

Maybe a dependency error. I'll suggest you to use a better practice for such lib.

  1. Put the fullcalendar scripts into vendor/assets/javascripts

  2. Require this script manually in application.js before the tree and after jquery and any other lib it depends.

    /=require 'fullcalendar`
    

Add

Check the loaded Javascript files in header, if application.js is the last, you have dependency error. The lib must be there before calling it.

Thursday, November 11, 2021
 
Yuriy Faktorovich
answered 3 Weeks ago
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