nodejs error _.isNull is not a function

To resolve the error "_.isNull is not a function" in Node.js, you can follow these steps:

  1. Import the lodash library: The error message suggests that the function _.isNull is not recognized. The function is part of the lodash library, so you need to import it into your Node.js script. To import lodash, you can use the following code at the beginning of your script:
const _ = require('lodash');
  1. Check lodash version: Ensure that you have a version of lodash that includes the _.isNull function. Older versions of lodash may not have this function. You can check your lodash version by running the following command in your terminal:
npm ls lodash

If you have an older version, you can update lodash by running:

npm update lodash
  1. Verify the usage of _.isNull: Double-check that you are using the .isNull function correctly. The correct usage of .isNull is:
_.isNull(value);

where value is the variable or expression you want to check for null.

  1. Check for typos or syntax errors: Make sure there are no typos or syntax errors in your code. Even a small mistake can cause the "_.isNull is not a function" error to occur. Check your code carefully, paying attention to any missing or extra characters.

  2. Ensure lodash is installed: Confirm that you have lodash installed in your project. You can do this by checking your package.json file or running the following command in your terminal:

npm ls lodash

If lodash is not listed as a dependency, you can install it by running:

npm install lodash

By following these steps, you should be able to fix the "_.isNull is not a function" error in your Node.js code.