vue 学习笔记（三）报错： TypeError: Cannot set property '0' of undefined

 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

})

}

总结：小心谨慎，注意每个值的赋值情况

 TypeError: Cannot set property '0' of undefined