{{ unless condition }} 

npm install ember-cli

ember new <project-name> --lang en

ember serve

ember generate route unless1

import Component from '@glimmer/component'; 
import { tracked } from '@glimmer/tracking'; 
import { action } from '@ember/object'; 
import { mapBy } from '@ember/object'; 
  
export default class extends Component { 
    student = [{ 
        "name": "Sam Snehil", 
        "age": 21 
    }, 
    { 
        "name": "Satyam Sahu", 
        "age": 23 
    }, 
    { 
        "name": "Sohan Argrwal", 
        "age": 25 
    }, 
    { 
        "name": "Sreya Sarma", 
        "age": 19 
    } 
    , 
    { 
        "name": "Satyam Sahu", 
    }]; 
  
  
    print(item) { 
  
        let ans = this.student.filterBy('name',item) 
        alert(JSON.stringify(ans)); 
    } 
}

{{yield}} 
<table> 
    <tr> 
        <th>Name</th> 
        <th>Age</th> 
    </tr> 
      {{#each this.student as |detail|}} 
  
    {{#unless detail.age}} 
    <tr> 
            <td>{{get detail 'name'}}</td> 
            <td>{{18}}</td> 
        </tr> 
    {{else}} 
            <tr> 
            <td>{{get detail 'name'}}</td> 
            <td>{{get detail 'age'}}</td> 
        </tr> 
    {{/unless}} 
    {{/each}} 
</table> 
<br/> 
{{textarea value=this.value}} 
<br/> 
<input type="button"
    id="set-code"
    value="Introduce Student" 
    {{action 'print' (mut this.value)}}/>

<Arr2> 
    <h1> 
        List of Student :  
    </h1> 
</Arr2> 
{{outlet}}

ember generate route unless2

import Component from '@glimmer/component'; 
import {tracked} from '@glimmer/tracking'; 
import { action, addObjects } from '@ember/object'; 
export default class CompactComponent extends Component { 
      
    items = ['Oxygen', 
        'Source Code', 
        'Infine', 
        'Tenet', 
        'SpiderHead', 
        'The Thing', 
        'A Quiet Place', 
        'The Invisible Man', 
        'Looper', 
        'Ad Astra',]; 
  
    @action 
    remove(data) { 
        this.items.removeObject(data); 
    } 
}

{{#unless @show}} 
  
This comoponent Don't Have block!!<br/> 
{{else}} 
<ul> 
<h3>{{yield}} : </h3> 
    {{#each this.items as |party|}} 
        <li>{{party}}</li> 
    {{/each}} 
</ul> 
<br /> 
{{textarea value=this.value}} 
<br/> 
<input
    type="button"
    id="check-atIndex"
    value="Remove"
    {{action "remove" this.value}} 
/> 
<br/><br/> 
{{/unless}}

<Arr @show={{true}}> 
    List of items 
</Arr> 
{{outlet}} 
<Arr/>