JavaScript 作用域链

• 一级一级往上找，找到了就停止，找不到就报错

let aa = 11
function f1() {
    let aa = 22
    function f2() {
        let aa = 33
        function f3() {
            let aa = 44
            console.log(aa)
        }
        f3()
    }
    f2()
}
f1()

// 输出44