JavaScript性能优化 - 减少作用域链查找层级

// 优化前
var name = 'leo';
function foo () {
    name = 'D.Leo';
    function baz () {
        var age = 38;
        console.log(age)
        console.log(name)
    }
    baz()
}
// 优化后
function foo () {
    var name = 'D.leo';
    function baz () {
        var age = 38;
        console.log(age);
        console.log(name)
    }
}
foo()