Cheap VPS & Xen Server


Residential Proxy Network - Hourly & Monthly Packages

Node.js Errors


The Node.js applications generally face four types of errors:

  • Standard JavaScript errors i.e. <EvalError>, <SyntaxError>, <RangeError>, <ReferenceError>, <TypeError>, <URIError> etc.
  • System errors
  • User-specified errors
  • Assertion errors

Node.js Errors Example 1

Let’s take an example to deploy standard JavaScript error – ReferenceError.

File: error_example1.js

  1. // Throws with a ReferenceError because b is undefined
  2. try {
  3.   const a = 1;
  4.   const c = a + b;
  5. catch (err) {
  6.   console.log(err);
  7. }

Open Node.js command prompt and run the following code:

  1. node error_example1.js

nodejs-error-example1

Node.js Errors Example 2

File: timer2.js

  1. const fs = require(‘fs’);
  2. function nodeStyleCallback(err, data) {
  3.  if (err) {
  4.    console.error(‘There was an error’, err);
  5.    return;
  6.  }
  7.  console.log(data);
  8. }
  9. fs.readFile(‘/some/file/that/does-not-exist’, nodeStyleCallback);
  10. fs.readFile(‘/some/file/that/does-exist’, nodeStyleCallback);

Open Node.js command prompt and run the following code:

  1. node error_example2.js

nodejs-error-example2.jpg

 

Comments

comments