小程序前端提示这个错误，麻烦大神帮忙看下，这个问题怎么解决

Question

VM361:1 thirdScriptError

Cannot read property '0' of undefined;at App onLaunch function;at api request success callback function

TypeError: Cannot read property '0' of undefined

    at Function.success (http://127.0.0.1:26749/appservice/app.js:26:193)

    at Object.success (http://127.0.0.1:26749/appservice/__dev__/WAService.js:3:14159)

    at c.<anonymous> (http://127.0.0.1:26749/appservice/__dev__/WAService.js:10:15121)

    at c.emit (http://127.0.0.1:26749/appservice/__dev__/WAService.js:4:28151)

    at Function.<anonymous> (http://127.0.0.1:26749/appservice/__dev__/WAService.js:10:16447)

    at http://127.0.0.1:26749/appservice/__dev__/WAService.js:4:9966

    at e (http://127.0.0.1:26749/appservice/appservice?t=1558957570107:11349:1896)

    at t.<anonymous> (http://127.0.0.1:26749/appservice/appservice?t=1558957570107:11349:1983)

    at t.emit (http://127.0.0.1:26749/appservice/appservice?t=1558957570107:11349:6315)

    at callback (http://127.0.0.1:26749/appservice/appservice?t=1558957570107:11349:14684)

Answer 1

应该是某个取数据的地方错了，代码中可能有个数组，但数组返回的是undefind，所以调用[0]就报错了，仔细看下数组赋值的地方，在取[0]时先判断下数组是否有值，如果有值再取[0]。

Answer 2

从问题描述来看，应该是请时的异步问题，试试promise 然后去了解下生命周期