前端调试技巧

1.console.log

console.log(test());     // 1
delete test;
console.log(typeof test);     // undefined

2.eval

  var GLOBAL_OBJECT = this;

  /* `foo` is created as a property of calling context Variable object,
      which in this case is a Global object */

  eval('var foo = 1;');
  GLOBAL_OBJECT.foo; // 1

3.delete 操作符

var o = { x: 1 };
delete o.x; // true
o.x; // undefined

http://www.cnblogs.com/jscode/archive/2012/09/02/2667464.html