FETCH API check for error code example

Example 1: how to handle fetch errors

function CheckError(response) {
  if (response.status >= 200 && response.status <= 299) {
    return response.json();
  } else {
    throw Error(response.statusText);
  }
}

// Now call the function inside fetch promise resolver
fetch(url)
  .then(CheckError)
  .then((jsonResponse) => {
  }).catch((error) => {
  });

Example 2: error handling in fetch

fetch("/api/foo")  .then(response => {    if (!response.ok) { throw response }    return response.json()  //we only get here if there is no error  })  .then(json => {    doSomethingWithResult(json)  })  .catch(err => {    err.text().then(errorMessage => {      displayTheError(errorMessage)    })  })

Tags:

Misc Example

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