Delete Web application using PowerShell in SharePoint 2013

To delete SharePoint Web application using PowerShell use this cmdlet:

Delete Web Application and All its zones:

#Web Application URL to delete
$WebAppURL="http://sharepoint.company.com" 

#sharepoint 2013 powershell delete web application
Remove-SPWebApplication -identity $WebAppURL -Confirm

This deletes the entire Web application and its all zones:

Remove Web Application Along with All its Databases and IIS Web Site:
To remove the Web application along with its content databases and the IIS Web site, use the switches: -DeleteIISSite and -RemoveContentDatabases

#Web Application URL to delete
$WebAppURL="http://sharepoint.company.com" 

#Remove the web application and its databases & IIS Web Application
Remove-SPWebApplication -identity $WebAppURL -Confirm -DeleteIISSite -RemoveContentDatabases

delete sharepoint web application using powershell

Delete the Extended Web Application zone:
To Removes the Extended Web Application zone, say: Internet, use:

#Web Application URL to delete
$WebAppURL="http://sharepoint.company.com" 

#sharepoint 2013 powershell delete web app
Get-SPWebApplication http://sitename | Remove-SPWebApplication -Zone "Internet" -Confirm

Make sure you logged in as a "Farm Administrator" with "Shell Access" rights to delete web applications using PowerShell