POST Requests in JavaScript

// POST JSON data
const response = await fetch('https://api.example.com/users', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    name: 'John Doe',
    email: 'john@example.com'
  })
})

// POST FormData (multipart/form-data)
const formData = new FormData()
formData.append('name', 'John Doe')
formData.append('avatar', fileInput.files[0])

const response = await fetch('https://api.example.com/users', {
  method: 'POST',
  body: formData  // No Content-Type header needed!
})

// POST URL encoded form
const params = new URLSearchParams()
params.append('username', 'john')
params.append('password', 'secret')

const response = await fetch('https://api.example.com/login', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/x-www-form-urlencoded',
  },
  body: params
})