关于javascript:js实现Functionprototypebind

Function.prototype.bind2 = function() {    const args = Array.from(arguments)    const context = args.shift() // context 在这个例子中指向 { x: 100 }    const self = this // self 在这个例子中指向 fn1    return function() {        const argsAll = args.concat(Array.from(arguments))        return self.apply(context, argsAll)    }}function fn1(a, b, c) {    console.log('this', this)    console.log(a, b, c)    return 'this is fn1'}const fn2 = fn1.bind2({ x: 100 }, 1)const res = fn2(2, 3)console.log(res)