[Javascript] 寫出好品質的code

來源

JavaScript uses functions to manage scope.
這些都是 Global variable
myglobal = "hello"; // antipattern console.log(myglobal); // "hello" console.log(window.myglobal); // "hello" console.log(window["myglobal"]); // "hello" console.log(this.myglobal); // "hello" 

這樣不好:
function sum(x, y) { // antipattern: implied global result = x + y; return result; }

需改成這樣:
function sum(x, y) { var result = x + y; return result; }

這樣不好: because a is local but b becomes global
function foo() { var a = b = 0; // ... }

需改成這樣:
var a = (b = 0); // or  function foo() { var a, b; // ... a = b = 0; // both local } 

待續...