1. (function () {
    2.     class Sub {
    3.         pond = []; //给实例设置的私有属性：this.pond=[]
    4.         on(func) {
    5.             let pond = this.pond;
    6.             if (pond.includes(func)) return;
    7.             pond.push(func);
    8.         }
    9.         off(func) {
    10.             let pond = this.pond,
    11.                 i = 0,
    12.                 item;
    13.             for (; i < pond.length; i++) {
    14.                 item = pond[i];
    15.                 if (item === func) {
    16.                     pond[i] = null;
    17.                     return;
    18.                 }
    19.             }
    20.         }
    21.         fire(...params) {
    22.             let pond = this.pond,
    23.                 i = 0,
    24.                 item;
    25.             for (; i < pond.length; i++) {
    26.                 item = pond[i];
    27.                 if (typeof item === 'function') {
    28.                     item(...params);
    29.                     continue;
    30.                 }
    31.                 pond.splice(i, 1);
    32.                 i--;
    33.             }
    34.         }
    35.     }
    37.     /* 暴露API */
    38.     if (typeof window !== 'undefined') window.Sub = Sub;
    39.     if (typeof module === 'object' && typeof module.exports === 'object') module.exports = Sub;
    40. })();

    使用如下

    1. let sub1 = new Sub;
    2. setTimeout(() => {
    3.     sub1.fire();
    4. }, 1000);
    6. let sub2 = new Sub;
    7. submit.onclick = function () {
    8.     sub2.fire();
    9. };
    11. const fn1 = () => console.log(1);
    12. const fn2 = () => console.log(2);
    13. const fn3 = () => console.log(3);
    14. const fn4 = () => console.log(4);
    15. const fn5 = () => console.log(5);
    16. sub1.on(fn1);
    17. sub1.on(fn2);
    18. sub1.on(fn3);
    20. sub2.on(fn2);
    21. sub2.on(fn3);
    22. sub2.on(fn4);
    23. sub2.on(fn5);