Function: watch()

function watch(
   source: object | Function, 
   cb: Function, 
   options: EffectOptions): void

监听响应式数据

Example

const count = ref(0);
watch(count, (newVal, oldVal) => {
 console.log(newVal, oldVal);
})
count.value = 1;
// 打印1 0

Parameters

Parameter	Type	Description
source	object | Function	副作用函数或者响应式对象
cb	Function	数据变化后回调函数
options	EffectOptions	配置

Returns

void