isEmpty-vs-isBlank

controllers.application.js

import Ember from 'ember';
import {isBlank, isEmpty} from '@ember/utils';
import {computed} from '@ember/object';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  x: 5,
  y: undefined,
  
  isBlankX: computed('x', function(){
    return isBlank(this.get('x'));
  }),
  
  isEmptyX: computed('x', function(){
    return isEmpty(this.get('x'));
  }),
  
  isBlankY: computed('y', function(){
    return isBlank(this.get('y'));
  }),
  
  isEmptyY: computed('y', function(){
    return isEmpty(this.get('y'));
  })
  
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
x : {{x}}
<br>
isBlankX : {{isBlankX}}
<br>
isEmptyX : {{isEmptyX}}
<br>
y : {{y}}
<br>
isBlankY : {{isBlankY}}
<br>
isEmptyY : {{isEmptyY}}
<br>
{{outlet}}
<br>
<br>

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-data": "3.4.2"
  }
}