function MyPromise(func) {    this.status = 'pending';    this.res = '';    this.thenCbs = [];    this.catchCbs = [];    const resolve = (data) => {        this.status = 'fulfilled';        this.res = data;        this.thenCbs.forEach(cb => {            cb(this.res);        });    }    const reject = (data) => {        this.status = 'rejected';        this.res = data;        this.catchCbs.forEach(cb => {            cb(this.res);        });    }    this.then = function (cb) {        if (this.status == 'pending') {            this.thenCbs.push(cb);        }        if (this.status == 'fulfilled') {            var res = cb(this.res)        }        return this;    }    this.catch = function (cb) {        if (this.status == 'pending') {            this.catchCbs.push(cb)        }        if (this.status == 'rejected') {            var res = cb(this.res)        }        return this;    }    func(resolve, reject)}