greater condition

gistfile1.txt

{
    "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
        "foo": {
            "type": "object",
            "defaultValue": {
                "vnetName": 0,
                "vnetAddressPrefix": "10.1.0.0/20",
                "dnsServers": [
                    
                ]
            }
        }
    },
    "resources": [
        {
            "condition": "[greater(length(parameters('foo').dnsservers),0)]",
            "type": "Microsoft.Storage/storageAccounts",
            "apiVersion": "2017-10-01",
            "name": "lkjl2kjfr",
            "location": "[resourceGroup().location]",
            "kind":"StorageV2",
            "sku": {
                "name":"Standard_GRS"
            }
        }
    ],
    "outputs": {
        "fooObject": {
            "type": "bool",
            "value": "[greater(length(parameters('foo').dnsservers),0)]"
        }
    }
}