title: mapping object with array of object to angular material mat table in angular 7
body: <p>I'm trying to display the object array which contain an array inside like </p>
  
  <pre><code>users=[
   { username:'xyz@gmail.com',firstname: 'XYZ',lastname:'yz',locations:['A','B','C']}]
  
  
  
  &lt;div class="mat-elevation-z8"&gt;
        &lt;table mat-table [dataSource]="dataSource" mat-sort&gt;  
          &lt;ng-container matColumnDef="username"&gt;
            &lt;th mat-header-cell *matHeaderCellDef mat-sort-header&gt; User Name &lt;/th&gt;
            &lt;td mat-cell *matCellDef="let row"&gt; {{row.username}}&lt;/td&gt;
          &lt;/ng-container&gt;
  
          &lt;ng-container matColumnDef="firstname"&gt;
            &lt;th mat-header-cell *matHeaderCellDef mat-sort-header&gt; First Name &lt;/th&gt;
            &lt;td mat-cell *matCellDef="let row"&gt; {{row.firstName}} &lt;/td&gt;
          &lt;/ng-container&gt;
  
          &lt;ng-container matColumnDef="lastname"&gt;
            &lt;th mat-header-cell *matHeaderCellDef mat-sort-header&gt; Last Name &lt;/th&gt;
            &lt;td mat-cell *matCellDef="let row"&gt; {{row.lastName}} &lt;/td&gt;
          &lt;/ng-container&gt;
  
  
          &lt;tr mat-header-row *matHeaderRowDef="displayedColumns"&gt;&lt;/tr&gt;
          &lt;tr mat-row *matRowDef="let row; columns: displayedColumns;"&gt;&lt;/tr&gt;
  
        &lt;/table&gt;
  
        &lt;mat-paginator [pageSizeOptions]="[5, 10, 25, 100]"&gt;&lt;/mat-paginator&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I want to show the data in location array .I don't know how to map it.please Help</p>