For system, network and cloud administrators
In order to be able to delete all Azure managed disks that start with mydisk, for example, you’ll first need to run the Azure Bash shell instead of PowerShell and then type:
az disk list --query "[?starts_with(name,'mydisk')].[name]" | xargs -L1 bash -c 'az disk delete --resource-group yourresourcegroup --name $0 --yes'
Using the –yes parameter will allow the command to say yes every time the deletion of a disk is done.