手写一个bind

Function.prototype.bind1 = function(){
            // 将类数组转化成数组
            let arr = Array.prototype.slice.call(arguments)
            
            //提取this
            const t = arr.shift()

            //保存当前this
            const self = this
            
            return function(){
                return self.apply( t, arr )
            }
}

function fn1(a,b,c){
    console.log(this)
    console.log(a,b,c)
    return 'this is fn1'
}
const fn2 =  fn1.bind1({x:100},1,2,3)
console.log(fn2())