React:TypeError: Cannot read properties of undefined (reading 'map')
解决方案
js中？问号代表可选项
可选链式操作符
参考链接
https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing_operator
js中？问号代表可选项
https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing_operator