expressjsHow do I get a parameter from an Express.js request?

To get a parameter from an Express.js request, you can use the req.params object. This object contains the route parameters that were defined when the route was registered. For example, if you had a route defined as app.get('/user/:id', (req, res) => { ... }), then you could access the id parameter in the request with req.params.id.

For example:

app.get('/user/:id', (req, res) => {
  const id = req.params.id;
  console.log(id);
});

Output example

123 (if the request was /user/123)

The req.params object is populated with all the route parameters that were defined when the route was registered. The keys in the object are the names of the parameters, and the values are the values that were provided in the request.

Here is a list of the parts of the example code and what they do:

• app.get('/user/:id', (req, res) => { ... }): this is the route definition. It defines a route that will respond to requests to /user/<id>, where <id> is a variable that can be accessed with req.params.id.

• const id = req.params.id;: this line gets the id parameter from the request and stores it in a variable.

• console.log(id);: this line prints the value of the id parameter to the console.

Helpful links

• Express Documentation - req.params

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