true or false if variable defined gotchas
<p>If a value must be defined to true or false, based off the check off another value, are there any gotchas in doing :</p>

<pre><code>!!someValue
</code></pre>

<p>Just a quick run against chrome's engine gives:</p>

<pre><code>boolCheck=function(someValue){
    return !! someValue;
}

console.log(boolCheck());           //false
console.log(boolCheck(undefined));  //false
console.log(boolCheck(null));       //false
console.log(boolCheck(1));          //true
console.log(boolCheck({va:1}));     //true
console.log(boolCheck("someTS"));   //true
console.log(boolCheck(boolCheck));  //true    
</code></pre>

<p>which SEEMS to work....</p>
