Cannot read properties of undefined (reading 'length'

控制台报错，使用 element-ui，el-table 在 template 中判断数组长度出错，

<el-table-column prop="forecastLogVos" label="最近预测表">
					<template slot-scope="scope">
						<div>
							{{ scope.row.forecastLogVos.length != 0 ? scope.row.forecastLogVos[scope.row.forecastLogVos.length-1].forecastTableName : '--' }}
						</div>
					</template>
</el-table-column>

报错原因要先判断数组是否存在，需要先对数组进行非空验证。即 scope.row.forecastLogVos != undefined。

<el-table-column prop="forecastLogVos" label="最近预测表">
					<template slot-scope="scope">
						<div>
							{{ scope.row.forecastLogVos != undefined && scope.row.forecastLogVos.length != 0 ? scope.row.forecastLogVos[scope.row.forecastLogVos.length-1].forecastTableName : '--' }}
						</div>
					</template>
</el-table-column>

错误解决！