Neat Thing I Learned Today – Part 1

In C, you can index arrays with either the array subscript inside of the typical square brackets:

arr[0]
or, with the less common (and somewhat mistifying):

0[arr]
Now, I’ve been using C for quite a while, but never realized that you could do this. It is definitely awesome, and could be really useful in some obfuscated programs. Now, just to make sure that this actually works, feel free to test it out. I wrote a really small sample program that runs a test (if it doesn’t work, please leave a comment with your compiler as I’d be interested to know if it doesn’t work on all platforms. Anyhow, feel free to use my source if you want.

The really interesting thing about this, is why it works. On the Stack Overflow discussion page for Strangest language feature, the user Michel explains why it works.

that’s because a[10] means *(a+10) … and 10[a] means *(10+a) :)

Pretty awesome. Anyhow, hope you learned something new, I sure did! Thanks Stack Overflow :)