How can I merge multiple tabs in a Google Spreadsheet using Google App Script?
<p>How can I merge multiple tabs in a Google Spreadsheet using Google App Script ? Data in all the tabs keep changing.</p>

<p>For example, I have 'Sheet1', 'Sheet2' and 'Sheet3' in a Google spreadsheet. Data in all these sheets have 3 columns - Name and email ID &amp; Region. Now, I want to merge/combine the data present in these 3 sheets/tabs into a 4th Sheet i.e. 'Sheet 4' having same Columns (name, email Id &amp; Region). The 4th sheet should have data as - data of Sheet1 followed by Sheet2 and then Sheet3. The number of rows in all the 3 sheets keeps changing. </p>