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jsLint Usage

Introducing jsLint.

JavaScript doesn't have a compiler that checks our syntax for us. There are some things about JavaScript, like semicolons, where things will work but it is not the right way to code. Is there a way to check our code? Yes!

jsLint is an online web application that will check your code and help you write JavaScript better and faster.

jsLint Overview

  • When you go to the jsLint site you have an area to enter your code and a settings area with a lot of check boxes.
  • Here are the steps to using jsLint.

  • Access the site at

  • Add the function list to the Global variables box.
  • Set the checkboxes in the settings area.
  • Copy and paste your code into the top text area.
  • Click on the button labelled jsLint.
  • Fix errors and issues that jsLint finds.
  • When you no longer get an errors box then you are done!

jsLint Settings

  • Here are the settings that match our course coding standards.
  • Add this string to the Global Variables box. This is a time when you should copy and paste.
prompt, alert, openEmployeePayrollRecords, openStudentExamRecords, openStudentEnrollmentRecords, openInventoryItemsRecords, openCustomerGasUsageRecords, isNumeric
  • Select checkboxes so that your settings look like this:

jsLint Settings

Entering Your Code

  • After you change the setting then copy your code from your editor and paste it into the large text area at the top. Press Ctl-A and copy the entire .js file. This way the line numbers of error messages will match your code.
  • Then click on the jsLint button.
  • Here's what this looks like:

jsLint Input

jsLint Errors

  • When you click the jsLint button you will a list of errors in your code.
  • After fixing your errors, click the jsLint button again.
  • Just keep fixing your code until the error list goes away.

jsLint Errors


  1. Lab02: jsLint
    • unit03/labs/lab-02-jsLint.html