为什么将 output 捕获为不同于变量的模板文字

Question

I was wondering why the following outputs are seen based on each scenario:

Assume i have a route with the following code:

app.get("/tasks", async (req, res) => {
  try {
    const tasks = await Task.find({});
    res.send(tasks)
  } catch (e) {
    res.status(500).send(`${e}`)
  }

Notice the last line in catch where i send the error, if I just type res.send(e) without the template literals a whole list of errors is generated with alot of errors.

{
    "stringValue": "\"5ef23a969ba85e6fa63\"",
    "kind": "ObjectId",
    "value": "5ef23a969ba85e6fa63",
    "path": "_id",
    "reason": {}
}

BUT, if I use res.send( ${e} ) ( put the error as a literal) A simple line is generated with summary of the error. CastError: Cast to ObjectId failed for value "5ef23a969ba85e6fa63" at path "_id" for model "Task"

Is it a feature of template literals or.. ?

Answer 1

The body parameter of send(parameter) can be:

• a Buffer object

• a String

• an object

• an Array

   res.send(Buffer.from('whoop')) res.send({ some: 'json' }) res.send('<p>some html</p>') res.status(404).send('Sorry, we cannot find that.') res.status(500):send({ error: 'something blew up' })

The template literal transforms your object into String : ${e} is a string.