React native 启动react本机应用程序时发生异常
我找不到哪里做错了 它发生在我运行Metro bundler时React native 启动react本机应用程序时发生异常,react-native,React Native,我找不到哪里做错了 它发生在我运行Metro bundler时 BUNDLE [android, dev] ./index.js ▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ 100.0% (1491/1491), done. LOG Running "Trepr" with {"rootTag":1} WARN Possible Unhandled Promise Rejection (id: 0): TypeError: Cannot read property 'length' of un
BUNDLE [android, dev] ./index.js ▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ 100.0% (1491/1491), done.
LOG Running "Trepr" with {"rootTag":1}
WARN Possible Unhandled Promise Rejection (id: 0):
TypeError: Cannot read property 'length' of undefined
TypeError: Cannot read property 'length' of undefined
at render (http://10.0.3.2:8081/index.bundle?platform=android&dev=true&minify=false:183726:35)
at finishClassComponent (http://10.0.3.2:8081/index.bundle?platform=android&dev=true&minify=false:17810:43)
您可以尝试获取
null
数组的属性legnth
。
所以你需要像这样编码
array !== null && array !== undefined && array.length
“length”有问题您必须在代码中将length与字符串或数组一起使用。