开发Discord Bot遇TypeError: Cannot read property 'send' of undefined求助

这个错误的根源很简单——你代码里出现了一个拼写错误！

看你helpCommand函数里的这一行：

if (arguments.length == 0) { receivedMessage.channnel.send("Im not sure what are you looking for.Try using `!help [topic]`") }

这里把channel拼成了channnel（多了一个'n'），导致receivedMessage.channnel是undefined，自然没法调用send方法，这就是报错的直接原因。

修正后的完整代码 #

只需要把拼写错误的channnel改成正确的channel即可，另外我还帮你调整了两处小细节让体验更顺畅：

if(receivedMessage.content.startsWith("!")) { processCommand(receivedMessage) }
function processCommand(receivedMessage) {
  let fullCommand = receivedMessage.content.substr(1)
  let splitCommand = fullCommand.split(" ")
  let primaryCommand = splitCommand[0]
  let arguments = splitCommand.slice(1)
  if (primaryCommand == "help") { helpCommand(arguments, receivedMessage) }
}
function helpCommand(arguments, receivedMessage){
  if (arguments.length == 0) { receivedMessage.channel.send("I'm not sure what you're looking for. Try using `!help [topic]`") }
  else { receivedMessage.channel.send("It looks like you need help with " + arguments.join(" ")) }
}

• 修正了原句里的语法小问题（"Im"→"I'm"，"are you"→"you're"）；
• 当用户输入多参数的!help指令时，用arguments.join(" ")把参数数组拼成完整的字符串，避免直接输出数组（比如输入!help setup bot，会显示"setup bot"而不是"setup,bot"）。

内容的提问来源于stack exchange，提问作者M. WALEED