countdown vue

                                    <template>
   {{ countDown }}
    <button type="button" v-on:click="countdown = 5"> setTimeout </button>
</template>
        
<script>
    export default {
        data() {
            return {
                countDown : 0
            }
        },
        method: {}
        watch: {
            countdown: function(val) {
                if(val > 0) {
                    setTimeout(() => {
                        this.countdown -= 1;
                    }, 1000);
                }
            },
        }
    }
</script>

                                    <template>
    {{ timerCount }}
</template>

<script>

    export default {

        data() {
            return {
                timerCount: 30
            }
        },

        watch: {

            timerCount: {
                handler(value) {

                    if (value > 0) {
                        setTimeout(() => {
                            this.timerCount--;
                        }, 1000);
                    }

                },
                immediate: true // This ensures the watcher is triggered upon creation
            }

        }
    }

</script>