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@StuPig
Last active October 4, 2015 14:27
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JS 的 作用域 作用域链 行参 实参 传值 而非 传址
/*
function a() {
// some operations
} // #1: 到这里会报错吗?
*/
// a(); // #2: 到这里会报错吗?
// 执行到#1 时不会报错
// 执行到#2 时会报错
// 为什么?
// 因为JS 是一种解释行语言,
var a = 1
, obj = {a: 'a'}
function num(a) {
// var a;
a = 10;
}
function ob(obj) {
// var obj;
obj = {a: 'b'}
// obj.a = 'b';
}
num(a);
ob(obj);
console.log(a); // 1
console.log(obj); // {a: 'a'}
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