What does NPM Update do?

NPM update command

This command updates all listed packages to the latest version (as determined by the version number in package.json) according to the Semver semantic version control module.

Here’s a simple example:

"react": "^" 15.6.1."react-dom": "~ 15.6.1".Copy the code

^: b allows left-most non-zero digits to be changed without modifying [Major, minor, patch] (matches the version numbers of updates Y, Z greater than X, Y, Z)

~: matches the version number of newer Z that is greater than X.Y.Z

So after NPM update, the react package will be updated to the latest version of 15.x.x, while the React -dom package will be updated to the latest version of 15.6.x.

Also, if package.json adds fields for packages, NPM Update will install those packages as well. If a field is deleted, the update command does not delete the corresponding package.