An important recent update to ARM templates was the usage of the object data type to parameters. A parameter of the object type can accept any valid JSON from external resources as its input at runtime. This helps colocate parameters for a resource and helps form a natural grouping of properties. The same parameter can also define a default object if the external source does not provide a value for this parameter.

Grouping parameters is also a workaround to overcome the limitation of 255 parameters in a template.

Grouping using objects makes it easy for a caller to specify parameter values, which is much more intuitive and easier to comprehend the parameters. For example, we could group all storage-related parameters so that they aren't scattered throughout an ARM template.

Once object parameters are defined, they can be referenced from within any section of the template. A complete example using the object parameter to provision a storage account is shown next.

The ARM Template code is as follows:

{
 "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
 "contentVersion": "1.0.0.0",
 "parameters": {
     "storageAccountConfiguration": {
         "type" : "object",
         "defaultValue" : {
             "name" : "sdw543fggsdfsd",
             "apiVersion" : "2018-02-01",
             "sku" : {
                 "name" : "Standard_LRS"
             }
         }
     }
 },
 "variables": {
 },
 "resources": [
 {
     "type": "Microsoft.Storage/storageAccounts",
     "name": "[parameters('storageAccountConfiguration').name]",
     "apiVersion": "[parameters('storageAccountConfiguration').apiVersion]",
     "location": "[resourceGroup().location]",
     "sku": {
         "name": "[parameters('storageAccountConfiguration').sku.name]",
     },
     "kind": "Storage"
     }
 ],

 "outputs": {
     "storageDetails": {
         "type": "string",
         "value": "[concat(parameters('storageAccountConfiguration').name,                                             parameters('storageAccountConfiguration').sku.name)]"
         }
     }
 }