SOURCE

function getNumber(number){
    var p = new Promise(function(resolve, reject, number){
        //做一些异步操作
        setTimeout(function(){
            console.log('number:' + number);
            var num = number ? number : Math.ceil(Math.random()*10); //生成1-10的随机数
            if(num<=5){
                resolve(num);
            }
            else{
                reject('数字太大了');
            }
        }, 2000);
    });
    return p;            
}


getNumber(1)
.then(function(data){
    console.log('resolved');
    console.log(data);
})
.catch(function(reason){
    console.log('rejected');
    console.log(reason);
});