ECMAScript function specification

Question

(Sorry if it is answered elsewhere)

I was reading ECMAScript 262 Specification (ECMAScript 5th Edition), and in 4.3.24 on function it says the following:

NOTE: In addition to its named properties, a function contains executable code and state that determine how it behaves when invoked. A functions code may or may not be written in ECMAScript.

Can someone point out or explain what does it mean that function can be written not in ECMAScript?

Thanks a lot in advance!

Answer 1

ECMAScript is a standard that is used in other languages aside from JavaScript such as JScript (Only supported in Internet Explorer, I think?) or ActionScript (Flash).

This statement means you can simply write other syntax in a function other than what is defined in ECMAScript.