^在package.json依赖版本中

Question

What does the ^ symbol mean in the version of a dependency in package.json?

I couldn't find it in the docs .

For example:

"dependencies": {
    "grunt": "^0.4.4",
    ...
}

Answer 1

I found an answer here :

The caret, on the other hand, is more relaxed. It will update you to the most recent major version (the first number). ^1.2.3 will match any 1.xx release including 1.3.0 , but will hold off on 2.0.0 . npm's semantic versioning parser clarifies the distinction:

 ~1.2.3 := >=1.2.3-0 <1.3.0-0 "Reasonably close to 1.2.3". ^1.2.3 := >=1.2.3-0 <2.0.0-0 "Compatible with 1.2.3". 

― isaacs/node-semver (emphasis added)

The relevant points from isaacs/node-semver are:

• ^1.2.3 := >=1.2.3-0 <2.0.0-0 Compatible with 1.2.3 .
  When using caret operators, anything from the specified version (including prerelease) will be supported up to, but not including, the next major version (or its prereleases). 1.5.1 will satisfy ^1.2.3 , while 1.2.2 and 2.0.0-beta will not.

• ^0.1.3 := >=0.1.3-0 <0.2.0-0 Compatible with 0.1.3 .
  0.xx versions are special: the first non-zero component indicates potentially breaking changes, meaning the caret operator matches any version with the same first non-zero component starting at the specified version.

• ^0.0.2 := =0.0.2 Only the version 0.0.2 is considered compatible