How do I validate query parameters in my API?

How do I validate query parameters in my API?

You can validate query parameters by checking their presence, type, and format using libraries like Joi or express-validator.

Can you show me an example using Express.js?

Sure! You can use middleware to validate parameters like this:

app.get('/api/data', (req, res) => {
  const { id } = req.query;
  if (!id || isNaN(id)) {
    return res.status(400).send('Invalid ID');
  }
  // Proceed with your logic
});

What if I want to validate multiple parameters?

You can validate multiple parameters by chaining checks or using a validation library. For example:

app.get('/api/data', (req, res) => {
  const { id, type } = req.query;
  if (!id || isNaN(id) || !type) {
    return res.status(400).send('Invalid parameters');
  }
  // Proceed with your logic
});