Created
March 4, 2015 03:18
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JavaScript作用域
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function a(x,y){ | |
y = function() { x = 2; }; | |
return function(){ | |
var x = 3; | |
y(); | |
console.log(x); | |
}.apply(this, arguments); | |
} | |
a(); |
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作用域的变量定义来自函数参数,var 定义,函数申明,否则继承自上层作用域。
以后 es6 增加 arrow function,block scope 和 default options 会更复杂