


A brief analysis of res.send() and res.end() in the node Express framework
This article will talk about node Express framework and learn about res.send() and res.end() in Express. I hope it will be helpful to everyone!
In the server-side code using Node.js
, if you are using the Express framework, then for a request, There are often two ways to respond:
// 方法1 app.get("/end", (req, res, next) =>{ res.end(xxx); }); // 方法2 app.get("/send", (req, res, next) =>{ res.send(xxx); });
So what is the difference between these two ways? What are their respective application scenarios? This is what I need to make clear today.
Express res.end()
Definition
It can end quickly without requiring any data response.
This method actually comes from Node core, specifically the response.end()
method of http.ServerResponse.Use
:
##Syntax
res.end([data[, encoding]][, callback])Parameter analysis:
- data
- encoding
- callback
- callback
##In-depth If you pass an object into the
res.end() method, an error will occur:
Express's res.send()
DefinitionSends an HTTP response message to the requesting client.
Syntaxres.send([body[,statusCode]])
The body parameter can be Buffer, Object, String, Boolean or Array.
Go deeperThrough code debugging, we can find that Express’s
res.send() method is ultimately called Also the response.end()
method of http.ServerResponse.Use
: <pre class='brush:php;toolbar:false;'>// node_modules/express/lib/response.js
res.send = function send(body) {
var chunk = body;
var encoding;
……
if (req.method === &#39;HEAD&#39;) {
// skip body for HEAD
this.end();
} else {
// respond
this.end(chunk, encoding);
}
return this;
};</pre>
Comparison
Same pointsThe similarities between Express's res.end() and res.send() methods:
- Both of them eventually return to
- The
response.end()
method of http.ServerResponse.Use
. Both will end the current response process.
DifferencesThe differences between Express’s res.end() and res.send() methods:
- The former can only send string or Buffer type, while the latter can send any type of data.
- From a semantic point of view, the former is more suitable for scenarios without any response data, while the latter is more suitable for scenarios with response data.
- Summary
When using the res.end() and res.send() methods of Express, it is generally recommended to use
res.send() method, so you don’t need to care about the format of the response data, because Express processes the data internally. ~This article is over, thank you for reading!
For more node-related knowledge, please visit:
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