我在NodeJS中遇到了[] .forEach的奇怪问题.
(使用NodeJs v5.4.1)
function _buildUserQuestionsForDisplay(question,callback){
var res = {}
["is_open","created","deleted","_id"].forEach(function(v){
res[v] = question[v]
})
...
...
}
抛出错误：
[“is_open”,”created”,”deleted”,”_id”].forEach(function(v){
TypeError: Cannot read property ‘forEach’ of undefined
如果我将代码更改为,它可以工作
var arr = ["is_open","_id"];
arr.forEach(function(v){
res[v] = question[v]
})
我已经在Chrome.console上测试了相同的功能,并且第一种方式正常工作.我知道两者都使用V8 JS引擎,这是一个bug还是我在Javascript规则中缺少的东西？
谢谢！
最佳答案
如果在此行之后没有分号,则代码会中断：
var res = {}
为了最大限度地减少这些问题,如果你不使用它,最好使用一个linter. JSHint和ESLint都可以作为开发插件添加到代码编辑器中(我使用ESLint和SubmlimeText中的Airbnb样式表),也可以使用Gulp或Grunt添加到工作流中,以便在提交代码之前捕获这些错误.
If you choose to omit semicolons where possible,my advice is to insert them immediately before the @R_301_126@ parenthesis or square bracket in any statement that begins with one of those tokens,or any which begins with one of the arithmetic operator tokens “/”,“+”,or “-” if you should happen to write such a statement. – 07002
