730202 - define a function in "if(){}"

Status: RESOLVED INVALID

(Core :: JavaScript Engine, defect)

Description

[ethan zheng]

User Agent: Mozilla/5.0 (Windows NT 6.1; rv:10.0.2) Gecko/20100101 Firefox/10.0.2
Build ID: 20120215223356

Steps to reproduce:

if(true){
    alert(typeof fn);
    function fn(){}
}


Actual results:

alert "undefined"


Expected results:

alert function

Comment 1

[Cork]

"Several widely used implementations of ECMAScript are known to support the use of FunctionDeclaration as a Statement. [...] It is recommended that ECMAScript implementations either disallow this usage of FunctionDeclaration or issue a warning when such a usage is encountered."[1]

[1] http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-262.pdf

Comment 2

[Cork]

to clarify the following is completely valid. But function declaration is parsed before the code runs so it would not be able to check the variables.

if(true) {
    var fn = function() {};
    alert(typeof fn);
}