vue 学习笔记（三）报错： TypeError: Cannot set property '0' of undefined_vue3typeerror: cannot set properties of undefined-优快云博客

本文链接：https://blog.youkuaiyun.com/qq_34633111/article/details/81026475

这篇博客详细记录了在学习Vue.js时遇到的一个常见错误——TypeError: Cannot set property '0' of undefined。作者通过具体的代码示例展示了问题发生的情况，并提供了解决此类问题的方法。

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TypeError: Cannot set property '0' of undefined

具体报错代码如下

    submit () {
      back.submitForm().then((response) => {
        let sets = []
        if (response.data !== undefined) {
          for (let i = 0; i < response.data.length; i++) {
            console.log(response.data[0].name)
            let groupinfo = {}
            groupinfo.name = response.data[i].name
            for (let j = 0; j < response.data[i].total; j++) {
              let ingroup = {}
              ingroup = response.data[i].powerSockets[j]
              groupinfo.items[j] = ingroup
            }
            sets[i] = groupinfo
          }
        }
        this.list = sets
      })
    }

groupinfo.items[j] = ingroup

该行报错，只找到空值。

解决方法：

submit () {
      back.submitForm().then((response) => {
        let sets = []
        if (response.data !== undefined) {
          for (let i = 0; i < response.data.length; i++) {
            console.log(response.data)
            let groupinfo = {}
            let ingroup = []
            if (response.data[i].powerSockets !== undefined) {
              for (let j = 0; j < response.data[i].total; j++) {
                let obj = {}
                obj.item = response.data[i].powerSockets[j].used
                ingroup[j] = obj
              }
            }
            groupinfo.name = response.data[i].name
            groupinfo.children = ingroup
            sets[i] = groupinfo
          }
        }
        this.list = sets
      })
    }