variable-copy-sample.json

{
  "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {},
  "variables": {
    "disk-array-on-object": {
      "copy": [
        {
          "name": "disks",
          "count": 5,
          "input": {
            "name": "[concat('myDataDisk', copyIndex('disks', 1))]",
            "diskSizeGB": "1",
            "diskIndex": "[copyIndex('disks')]"
          }
        }
      ]
    },
    "copy": [
      {
        "name": "disks-top-level-array",
        "count": 5,
        "input": {
          "name": "[concat('myDataDisk', copyIndex('disks-top-level-array', 1))]",
          "diskSizeGB": "1",
          "diskIndex": "[copyIndex('disks-top-level-array')]"
        }
      }
    ]
  },
  "resources": [],
  "outputs": {
    "exampleObject": {
      "value": "[variables('disk-array-on-object')]",
      "type": "object"
    },
    "exampleArrayOnObject": {
      "value": "[variables('disk-array-on-object').disks]",
      "type" : "array"
    },
    "exampleArray": {
      "value": "[variables('disks-top-level-array')]",
      "type" : "array"
    }
  }
}