fetch api

// Example POST method implementation:
async function postData(url = '', data = {}) {
  // Default options are marked with *
  const response = await fetch(url, {
    method: 'POST', // *GET, POST, PUT, DELETE, etc.
    mode: 'cors', // no-cors, *cors, same-origin
    cache: 'no-cache', // *default, no-cache, reload, force-cache, only-if-cached
    credentials: 'same-origin', // include, *same-origin, omit
    headers: {
      'Content-Type': 'application/json'
      // 'Content-Type': 'application/x-www-form-urlencoded',
    },
    redirect: 'follow', // manual, *follow, error
    referrerPolicy: 'no-referrer', // no-referrer, *no-referrer-when-downgrade, origin, origin-when-cross-origin, same-origin, strict-origin, strict-origin-when-cross-origin, unsafe-url
    body: JSON.stringify(data) // body data type must match "Content-Type" header
  });
  return response.json(); // parses JSON response into native JavaScript objects
}

postData('https://example.com/answer', { answer: 42 })
  .then(data => {
    console.log(data); // JSON data parsed by `data.json()` call
  });

// Error handling while fetching API

const url = "http://dummy.restapiexample.com/api/v1/employee/40";
fetch(url) //404 error
     .then( res => {
          if (res.ok) {
                return res.json( );
          } else {
                return Promise.reject(res.status); 
           }
      })
      .then(res => console.log(res))
      .catch(err => console.log('Error with message: ${err}') ); 

// Making get requests

const url = "http://dummy.restapiexample.com/api/v1/employees"; 
fetchurl()
     .then(res => {
            console.log(res);
})
      .catch(err => {
             console.log('Error: ${err}' ); 
});

// Fetch and Async/Await

const url = 'http://dummy.restapiexample.com/api/v1/employees'; 
const fetchUsers = async () => {
    try {
       const res = await fetch(url);
     // check for 404 error
       if (!res.ok) { 
           throw new Error(res.status);
       }
       const data = await res.json();
          console.log(data);
       }
       // catch block for network errors
       catch (error) { 
            console.log(error); 
        }
}
fetchUsers( );

// Making post request

const url = 'http://dummy.restapiexample.com/api/v1/create'
const user = {
      name: 'Rahul'
      age: '16'
      salary: '000'
};

const options = {
   method: 'POST'
   body: JSON.stringify(user), 
}

fetch(url, options)
     .then( res => res.json())
     .then( res=> console.log(res));