How to write elegant and readable JavaScript code

Even if is the simplest requirement, and different programmers will write code that is not the same:

Requirements: Top-up procedures are not eligible to recharge the amount of money, that can only be charged to 100, 200, 500, 1000 amount, other worry:

1. Novice programmers may write this, though readable, code-verbose, and not elegant.

$ (function () {            var recharge = +;            if (Recharge | | | recharge | | | = = Recharge | | recharge = +) {//to do                some thing!            }        });

2. Veteran programmers may write this, the code is concise, but the readability is weak.

1 $ (function  () {2             var recharge = +; 3 4             if (/1000| ([1,2,5][0]{1,2})/g.test (Recharge)) {5                 //to dosome thing! 6             }7         });

3. The recommended wording is this, both elegant and readable.

$(function() {Array.prototype.inArray=function(func, item) {varCur = This;  for(varIdxinchcur) {                    if(func (Cur[idx], item)) {return true; }                }                return false;            }; varRecharge = 100; if([1000].inarray,function(i, cur) {returni = =cur; }, Recharge)) {//To do some thing!            }        });

How to write elegant and readable JavaScript code