js手动实现bind教程

function.prototype.bind=function(obj){
    var arg=array.prototype.slice.call(arguments,1);
    var context=this;
    var bound=function(){
      arg=arg.concat(array.prototype.slice.call(arguments));
      return context.apply(obj,arg);
    }
    var f=function(){}
    f.prototype=context.prototype;
    bound.prototype=new f();
    return bound;
}

function read(name, time, book) {
    console.log(`${name} is reading ${book} at ${time}`)
}

var tomread = read.bind(this, 'tom', 'morning')
tomread('<万历十五年>')
console.log(tomread.bind)