将变量传递给函数范围

Question

是否可以在不传递参数的情况下以其他方式执行以下操作？

var f = function(){
    console.log(v);
}

var original = f;

f = function(){
    var v = "test";
    original();
};

// the following line is called by 3rd party code
f();  // it errors out here - v is not defined

Answer 1

将var v设为全球变量

var v ;
var f = function(){
  v="new test"
    console.log(v);
}

var original = f;

f = function(){
     v = "test";
    original();
};

f();//f function
original();//original function also working

Answer 2

使用可以在这里使用JavaScript Closures

function f() {
    var v = 'test';
    return (function () {
        console.log(v)
    })();
}

Answer 3

另一种方法：

var f = function(){
    console.log(arguments[0]);
};

f = f.bind(null, 'test');

f();