yardfarmer/jsbin.wutep.html

## jsbin.wutep.html
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>闭包是由作用域链引起的</title>
</head>
<body>
在javascript中,作用域是词法化作用域,是方法在定义的时候已经确定的,与调用无关.作用域链创建早于方法调用,得益于此,我们方能使用闭包.
</body>
</html>

## jsbin.wutep.js
var countUpFromZero = function() {
  var count = 0;
  return function() {
    return ++count;
  };
}();

console.log(countUpFromZero());
console.log(countUpFromZero());
console.log(countUpFromZero());
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	<title>闭包是由作用域链引起的</title>
	</head>
	<body>
	在javascript中,作用域是词法化作用域,是方法在定义的时候已经确定的,与调用无关.作用域链创建早于方法调用,得益于此,我们方能使用闭包.
	</body>
	</html>
	var countUpFromZero = function() {
	var count = 0;
	return function() {
	return ++count;
	};
	}();

	console.log(countUpFromZero());
	console.log(countUpFromZero());
	console.log(countUpFromZero());