So people always say that in JavaScript semicolons are optional but you had better use them anyway. The often cited case is the return statement.

{% highlight javascript %} function foo() { console.log(‘executing foo!’)

// even though there is no semicolon, we just return immediately return { data: ‘data’ } }

console.log(foo()); {% endhighlight %}

Jsbin link.

In JavaScript you can make new code block ”{ }” anywhere you want and it is perfectly valid, it will just execute when the code path hits it. Another funny thing is that for some reason an if without a body and semicolon following it is valid (e.g. “if(true);” will not throw any error). So if you bring these two things together you can get a weird thing like this:

{% highlight javascript %} function foo() { console.log(‘running foo…’)

if(false); { console.log(‘code block in if statement executed’) } }

foo() {% endhighlight %}

jsbin link.