参考1

vue js 实例

    <script type="text/javascript">
    export default {
        mounted:function(){
            this.f1(this.f2);
            this.f3();
        },
        methods:{
            f1(callback){
                console.log('f4')
                setTimeout(function(){
                    console.log('f1')
                    callback();
                },0)
            },
            f2(){
                console.log('f2')
            },
            f3(){
                console.log('f3')
            },
        },
    }

    </script>

结果 f4 f3 f1 f2

setTimeout 是异步的，time == 0 也一样