update

Author: mumian

articles/azure-resource-manager/bicep/diagnostics/bcp414.md

@@ -1,67 +1,45 @@
 ---
 title: BCP414
-description: The spread operator "..." is not permitted in this location.
+description: The `^` indexing operator cannot be used on base expressions of type <base-type>.
 ms.topic: reference
 ms.custom: devx-track-bicep
 ms.date: 05/20/2025
 ---
 
 # Bicep diagnostic code - BCP414
 
-This diagnostic occurs when you use expressions to define resource bodies as the [`Spread`](../operator-spread.md) operator gets converted to a function. It's a limitation in JSON.
+This diagnostic occurs when the reverse index operator (^) is used on an expression of an unsupported type, such as object, bool, or int. 
 
 ## Description
 
-The spread operator "..." is not permitted in this location.
+The `^` indexing operator cannot be used on base expressions of type \<base-type>.
 
 ## Level
 
 Error
 
 ## Examples
 
-The following example raises the diagnostic because the `spread` operator is used to define the resource body:
+The following code attempts to use the ^ operator on an object, which triggers BCP414.
 
 ```bicep
-param location string = resourceGroup().location
-param addressPrefix string = '10.0.0.0/24'
- 
-resource vnet 'Microsoft.Network/virtualNetworks@2024-01-01' = {
-  name: 'vnetName'
-  location: location
- 
-  ...(addressPrefix != '' ? {
-    properties: {
-      addressSpace: {
-        addressPrefixes: [
-          addressPrefix
-        ]
-      }
-    }
-  } : {})
+var config = {
+  name: 'example'
+  value: 42
 }
+
+output result any = config[^1] // Error: BCP414 - The "^" indexing operator cannot be used on base expressions of type "object".
 ```
 
-You can fix the diagnostic by using the operator in the lower level:
+To access properties of an object, use the `.` operator instead of `^`. The following code corrects the previous example.
 
 ```bicep
-param location string = resourceGroup().location
-param addressPrefix string = '10.0.0.0/24'
- 
-resource vnet 'Microsoft.Network/virtualNetworks@2024-01-01' = {
-  name: 'vnetName'
-  location: location
- 
-  properties: {
-    addressSpace: {
-      ...(addressPrefix != '' ? {
-        addressPrefixes: [
-          addressPrefix
-        ]        
-      } : {})
-    }
-  }
+var config = {
+  name: 'example'
+  value: 42
 }
+
+output result string = config.name
 ```
 
 ## Next steps