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Mary Gathoni
Mary Gathoni

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Express: req.params, req.query and req.body

These three, req.body, req.query and req.params are part of Express request object.
They are used by the client to send data to the server.
This post outlines their differences and gives examples on how to use them.

1. req.body

Generally used in POST/PUT requests.
Use it when you want to send sensitive data(eg. form data) or super long JSON data to the server.

How to send data in request body

  • using curl
  curl -d '{"key1":"value1", "key2":"value2"}' -H "ContentType: application/json" -X POST http://localhost:3000/giraffe
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  • using axios
  axios.post('/giraffe', {
    key1: 'value1',
    key2: 'value2'
  })
  .then(response => {
    ...
  })
  .catch(error => {
    ...
  })
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How to get data from request body

  app.get('/giraffe', (req, res) => {
   console.log(req.body.key1) //value1
   console.log(req.body.key2) //value2
  })
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Remember to use express.json() middleware to parse request body else you'll get an error

app.use(express.json())
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2. req.params

These are properties attached to the url i.e named route parameters. You prefix the parameter name with a colon(:) when writing your routes.

For instance,

  app.get('/giraffe/:number', (req, res) => {
   console.log(req.params.number)
  })
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To send the parameter from the client, just replace its name with the value

  GET  http://localhost:3000/giraffe/1
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3. req.query

req.query is mostly used for searching,sorting, filtering, pagination, e.t.c
Say for instance you want to query an API but only want to get data from page 10, this is what you'd generally use.
It written as key=value

  GET  http://localhost:3000/animals?page=10
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To access this in your express server is pretty simple too;

  app.get('/animals', ()=>{
   console.log(req.query.page) // 10
  })
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I hope you found this helpful.

Thanks for reading 🥰.

Cover Photo by Adi Goldstein on Unsplash

Top comments (10)

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ddelimond profile image
Darren Delimond

Great article!

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vats_lalit_6dae2af8e56d66 profile image
Vats Lalit

Easy explanation Great

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mosindo profile image
Mosindo

Merci Mary

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freenrg profile image
freenrg

Thank you Mary! That was very useful. Great teaching style!

I would like to connect with you or follow you on LinkedIn but I cannot find your profile. Do you have one?

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tichel profile image
tichel

how to manage a request with a body and params (together)?

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salmanfarcy profile image
salman farcy

great

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fasalgafoor profile image
fasalgafoor

thanks

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deekshithhh profile image
Deekshith

Thanks

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arslan3693 profile image
Arslan Ahmed

This was helpful

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webafrique profile image
webAfrique

Thanks soooo much Mary, this has helped solve an issue I have had for the past week.