Why is JavaScript's post-increment operator different from C and Perl?

Question

I\'m studying for an exam on JavaScript at the moment. I\'ve also got a little knowledge of C and Perl so I\'m familiar with prefix and postfix operators in all three langua

Answer 1

Basically, the value of x is decemented after assignment. This example might make it clearer (run in Firebug console)

var x = y =10;    
x += y--;        
console.log(x , y); // outputs 20 9