如何在 Express.js 中结束循环以在“*”下看到一些内容

Question

我试图在 Express.js 中使用一个循环，但无法结束它。

我的循环总是写“你好”，我在 /hello/SomeNumber 之后打印（例如 /hello/5）并显示 5 个你好。

我希望它在 >3 之后停止并在“*”下显示消息。

app.get("/repeat/:word/:numbers", function(req, res) {
  var word = req.params.word;
  var numbers = Number(req.params.numbers);
  var lol = ""
  for (var i = 1; i <= numbers; i++) {
    lol += word + " ";
  }
  res.send(lol);
});


app.get("*", function(req, res) {
  res.send("Sorry, page not found...What are you doing with your life?");
});

app.listen(process.env.PORT, process.env.IP, function() {
  console.log("Server has started!!!");
});

Answer 1

使用中断；

for (var i = 1; i <= numbers; i++) {
  if(i>3)
  break;
   lol +=  word + " ";
}

Answer 2

是这样的吗？

app.get("/repeat/:word/:numbers", function(req, res) {
    var word = req.params.word;
    var numbers = Number(req.params.numbers);
    if (numbers > 3) {
        res.send("Sorry, page not found...What are you doing with your life?");
    } else {
        var lol = ""
        for (var i = 1; i <= numbers; i++) {
            lol += word + " ";
        }
        res.send(lol);
    }

});

编辑：在 OP 接受了 Enthusiastic Developer 的回答后，我的回答不再被接受，据我所知这会给出错误原因，next() 在循环中，这会给出错误Error: Can't set headers after they are sent.

如果您确定要使用中间件来捕获所有请求，那么这里：

app.get("/repeat/:word/:numbers", function(req, res, next) {
    var word = req.params.word;
    var numbers = Number(req.params.numbers);
    if (numbers > 3) {
        next();
    } else {
        var lol = ""
        for (var i = 1; i <= numbers; i++) {
            lol += word + " ";
        }
        res.send(lol);
    }
});


app.all("*", function(req, res) {
    res.send("Sorry, page not found...What are you doing with your life?");
});

Answer 3

伙计，上面的人不理解这个任务。如果迭代次数超过 3，则需要跳转到下一个中间件，对吗？

试试这个：

var express = require('express');
var app = express();

app.get('/repeat/:word/:numbers', function(req, res, next) {
  var word = req.params.word;
  var numbers = Number(req.params.numbers);
  var lol = '';
  for (var i = 1; i <= numbers; i++) {
    if (i > 3) next()
    lol += word + ' ';
  }
  res.send(lol);
});

app.get('*', function(req, res) {
  res.send('Sorry, page not found...What are you doing with your life?');
});

app.listen(process.env.PORT, process.env.IP, function() {
  console.log('Server has started!!!');
});

Answer 4

这是我的解决方法。在循环中添加一个 if 语句来检查数字是否 > 3。如果是，使用 break 停止循环并将 * 路由中的文本分配给 lol 变量。然后在调用 'res.send' 时路由函数的末尾，它包含 n * hallo 或 "Sorry, page not found...What are you doing with your life?"

这是代码。希望对您有所帮助。

app.get("/repeat/:word/:numbers", function(req, res) {
  var word = req.params.word;
  var numbers = Number(req.params.numbers);
  var lol = ""
  for (var i = 1; i <= numbers; i++) {
    if (numbers > 3) {
      break;
      lol = 'Sorry, page not found...What are you doing with your life?';
    } else {
      lol += word + " ";
    }
  }
  res.send(lol);
});


app.get("*", function(req, res) {
  res.send("Sorry, page not found...What are you doing with your life?");
});

app.listen(process.env.PORT, process.env.IP, function() {
  console.log("Server has started!!!");
});

如何在 Express.js 中结束循环以在“*”下看到一些内容

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