var length = 1
function fn() {
console.log(this.length)
}
var obj = {
length: 100,
action: function(callback) {
// 输出1
callback()
// 输出2
arguments[0]()
// 输出3
var foo = arguments[0]
foo()
// 输出4
this.foo2 = arguments[0]
this.foo2()
}
}
var arr1 = [1, 2, 3, 4]
obj.action(fn, ...arr1)
// 引题
var length = 1
function foo() {
console.log(this.length)
}
var arr2 = [foo, 2, 3]
arr2[0]()
var f1 = arr2[0]
f1()