arm-template-function.json

{
    "$schema": "http://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
    "contentVersion": "1.0.0.0",
    "functions": [
        {
            "namespace": "rt",
            "members": {
                "containerNameWithLocation": {
                    "parameters": [
                        {
                            "name": "containerName",
                            "type": "string"
                        }
                    ],
                    "output": {
                        "type": "string",
                        "value": "[concat(parameters('containerName'), resourceGroup().location)]"
                    }
                }
            }
        }
    ],
    "parameters":{
     "containerName": {
            "type": "string",
            "defaultValue": "blobcontainer"
        }
    }
}