title: Angular9 / Typescript apex caracter ' VS ` (Backtick or Accento Grave)
body: <p>I have this pipe.ts class:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>import { Pipe, PipeTransform } from '@angular/core';
  
  @Pipe({
    name: 'discount'
  })
  export class DiscountFormatterPipe implements PipeTransform {
  
    // ?: should means that the variable is not mandatory
    transform(value: number, discount: number, is_special?: boolean, args?: any): any {
      if(!Number.isInteger(value)) return value;
  
      let text = String(value);
      let discountedValue = value - discount;
      text = `You save &lt;del&gt;${value}&lt;/del&gt; &lt;b&gt;${discountedValue}&lt;/b&gt;`;
      debugger;
      
      return text;
    }
    
  
  }</code></pre>
  </div>
  </div>
  </p>
  
  <p>I discovered that it is different to write:</p>
  
  <pre><code>text = `You save &lt;del&gt;${value}&lt;/del&gt; &lt;b&gt;${discountedValue}&lt;/b&gt;`;
  </code></pre>
  
  <p>instead of:</p>
  
  <pre><code>text = 'You save &lt;del&gt;${value}&lt;/del&gt; &lt;b&gt;${discountedValue}&lt;/b&gt;';
  </code></pre>
  
  <p>changing apex type. The second syntax doesn't work. What change between `` and '' ? What is the real name of  `, how I can make it without do copy paste and what are his funcionality?</p>