parseInt vs unary plus, when to use which?

Question

What are the differences between this line:

var a = parseInt(\"1\", 10); // a === 1

and this line

var a = +\"1\"; // a ===          


        

Answer 1

Consider performance too. I was suprised that parseInt beats unary plus on iOS :) This is helpful for web apps with heavy CPU consumption only. As a rule-of-thumb I'd suggest JS opt-guys to consider any JS operator over another one from the mobile performance point of view nowadays.

So, go mobile-first ;)