reduce 重写filter

const fil = function(fn,context){
    return this.reduce(function (pre,cur,index) {
        return fn.call(this,cur,index) ? [...pre, cur]: [...pre]
    },[])

}

Array.prototype.fil = fil;
const cc = [111,222,323,4111,1].fil(function (item,index,arr) {
    console.log(item)
    if (item>111){
        return  item;
    }

})
console.log(cc)