Error in callback for watcher "candidates": "TypeError: Cannot read properties of undefined (reading 'toString')"
时间: 2023-11-28 10:43:47 浏览: 278
这个错误提示是在监视candidates属性的回调函数中出现了一个undefined对象,而在这个undefined对象上调用了toString方法,导致了TypeError。解决这个问题的方法是检查代码中是否正确地定义了candidates属性,以及在回调函数中是否正确地使用了candidates属性。如果candidates属性是一个对象,那么需要确保它已经被正确地初始化了,否则在回调函数中访问它的属性或方法时就会出现undefined。如果candidates属性是一个数组,那么需要确保它已经被正确地赋值了,否则在回调函数中访问它的元素时也会出现undefined。
相关问题
Error in callback for watcher "echartData": "TypeError: Cannot read properties of undefined (reading 'length')"
以下是关于"Error in callback for watcher 'echartData': 'TypeError: Cannot read properties of undefined (reading 'length')'"的解释和演示:
1. 对象属性检查
```javascript
var b = {name:1}
console.log(b.hasOwnProperty('name')) // 输出:true
```
2. Promise执行顺序
```javascript
const p1 = new Promise((resolve, reject) => {
setTimeout(() => {
resolve(1)
throw new Error('p1失败信息')
}, 2000)
})
const p2 = p1
.then((val) => {
console.log(val, 'p2成功返回的')
return val + 1
})
.catch((err) => {
console.log(err, 'p2失败返回的')
return err
})
Promise.all([p2, Promise.reject(3)])
.then((val2) => {
console.log(val2, 'all成功返回的')
})
.catch((err2) => {
console.log(err2, 'all失败返回的')
})
```
Error in callback for watcher "inventoryList": "TypeError: Cannot read properties of undefined (reading 'apply')"
这个错误提示的意思是在监视属性"inventoryList"的回调函数中发生了一个错误,具体是"TypeError: Cannot read properties of undefined (reading 'apply')"。这个错误通常是由于在定义监视器时未正确设置回调函数引起的。解决这个问题的方法是确保正确定义监视器的回调函数,并确保函数名没有拼写错误。您可以检查一下代码中与"inventoryList"相关的监视器的回调函数是否正确设置,以及是否存在拼写错误。<span class="em">1</span><span class="em">2</span><span class="em">3</span>
#### 引用[.reference_title]
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