Javascript method declaration -

is right declare method this?

window['test']['myfunction?'] = function(param) {         for(var in([ param.getelementsbytagname('ol'), param.getelementsbytagname('ul') ]){ found += a.length(); }         return != 0             ? true             : false;     } 

i use declare method this

var test = function(param){ ... } 

but saw first declaration in code. not able that. what's difference in these 2 type of declaration. 1 more efficient?

in javascript, virtually object meaning has set of properties. can access or set these properties in few ways, 2 of relevant here.

the first option window.foo = 'bar';. way write window['foo'] = 'bar'; first 1 called dot notation, second 1 called bracket notation. bracket notation has 1 advantage on dot notation, type of characters can use. example window.invalid-foo = 'bar' not work. window['invalid-foo'] on other hand does.

now question; there possibility when encountering window['test']['myfunction?'] original author of code has own framework checks global window.test object functions. , iterates through these functions , calls them way of testing code.

i not recommend doing things way because:

1. you're polluting global namespace.
2. you're creating unnecessary confusion using non-standard approach declaring variables.

is 1 way of declaring functions faster other? latter faster enormous amount. we're talking 2 million operations per second versus 1.5 billion operations per second.