little javascript discoveries, aka shame on me :)

Shame on me, after going through this cheatsheet I have realized there were some things I didn't know about javascript:

•  variables declared with var are declared locally, variables declared without var are not;
• to check whether the value is undefined, one has to use the following construct: 
• if (x === undefined)
• and NOT if (x==undefined) because it will always be true.

They forgot to clearly mention the difference between normal arrays:

• x = [1,2,3];

and associative arrays

• x = {'a':1, 'b':2, 'c':3};

though they do refer to those as "hash literals" (the document seems to be a bit old though).