購読——発表者モードが簡単に実現されます.

//      Even 
class Even{
    constructor(){
        this._events = {};  //    ，          ，         ，               
    }

    $on(even,fn){
       if(this._events[even]){ //      ， fn       
           this._events[even].push(fn);
       }else{    //        ，          ，                   
           this._events[even] = [];
           this._events[even].push(fn);
       }
    }

    $emit(even){ //      
       if(this._events[even]){ //        ，      
           this._events[even].forEach(fn => void fn());
       }
    }
}

//  

let today = new Even(); //  today      
//  
today.$on("goToSchool",carryYourBag);//         
today.$on("goToSchool",rideBicycle);
today.$on("goToSchool",sayHiToTeacher);

//  
today.$emit("goToSchool");

//         
function carryYourBag(){
    console.log("      ！");
}

function rideBicycle(){
    console.log("       ！");
}

function sayHiToTeacher(){
    console.log("      ，        ！");
}