From a conversation on the Working Code Podcast Discord channel I came across a change between Lucee 5 to Lucee 6, and how variables are scoped and handled, specifically when/if using var in a .cfm template. This post is just the sample code I used to do some digging on how the scoping differences between the two versions using a simple test cases to show the different outcomes

Test Scenario

Here are my test files, var.cfm and varinclude.cfm.

var.cfm (main template):

<cfscript>
  var a = "a";
  b = "b";
  local.c = "c";

  dump(a); // Output: "a"
  dump(b); // Output: "b"
  dump(c); // Output: "c"
  dump(local.c); // Output: "c"

  cfinclude(template="varinclude.cfm");
</cfscript>

varinclude.cfm (included template):

<cfscript>
  dump(a); // Output: "a"
  dump(b); // Output: "b"
  dump(c); // Output: "c"
  dump(local.c); // Output: "c"
</cfscript>

This setup works well on Lucee 5, where:

• The var keyword is used to declare variables with function-local scope, even outside functions.
• The variable b is implicitly scoped to the current page.
• The local scope is explicitly used for c.

Results on Lucee 5

On Lucee 5, the following outputs occur:

• dump(a); outputs "a".
• dump(b); outputs "b".
• dump(c); outputs "c".
• dump(local.c); outputs "c".

The included template (varinclude.cfm) inherits these variables, and everything behaves as expected. This is because, in Lucee 5, var declarations work even outside of functions.

Behaviour in Lucee 6

When upgrading to Lucee 6, however, some changes in scoping rules cause issues:

1. Using var outside a function:

   <cfscript>
     var a = "a"; // This line fails with "Can't invoke key A, Local Scope can only be invoked inside a Function"
   </cfscript>
   

   In Lucee 6, the var keyword is now restricted to function scopes, and attempting to use it outside a function will result in an error. This is a notable shift from Lucee 5.

   

2. Accessing c without scoping:

   <cfscript>
     dump(c); // This line fails with "variable [C] doesn't exist"
   </cfscript>
   

   Lucee 6 enforces stricter scoping rules. Without explicitly declaring c in a shared scope (such as local.c), it's no longer accessible in the same way as in Lucee 5.

   

TL;DR

When migrating from Lucee 5 to Lucee 6, developers need to be aware of the stricter scoping rules. var is now restricted to function scope in Lucee 6. Attempting to use it outside of a function will result in an error.