在package.json文件中所依赖的模块版本会有不同的写法，有时候会忘记其用法，现记录如下，以便后续查阅。
依赖模块都是用一个简单的并且带有包名称和版本范围的对象指定，而这个版本范围是一串由一个或者多个空格分隔符组成的字符串；此外，依赖模块还可以通过tarball或者git URL来标识。注意了，不要将测试工具和转换器模块放置在依赖模块中，这些模块应该放置在开发依赖模块中。
version必须精确匹配版本>version必须比设置的版本要高>=version大于或等于该版本<version 小于该版本<=version 小于或等于该版本- x-ranges的用法
在[major, minor, patch]的元组中，X、x、*的任何一个符号通常用来替代一个数值，
* := >=0.0.0 任何版本都符号 1.x := >=1.0.0 <2.0.0 匹配主版本（major版本） 1.2.x := >=1.2.0 <1.3.0 匹配主版本和次版本(major and minor versions) X-range形式的版本，X、x、*这些特殊字符是可选的，如下面的例子所示： "" (empty string) := * := >=0.0.0 1 := 1.x.x := >=1.0.0 <2.0.0 1.2 := 1.2.x := >=1.2.0 <1.3.0
~version 在比较值中若指定了次要版本（minor version），那么允许patch-level版本可以发生变化；若没有指定次要版本（minor version），那么允许次要版本（minor version）可以发生变化。Tilde Ranges具体用法可以参考下面示例：
~1.2.3 := >=1.2.3 <1.(2+1).0 := >=1.2.3 <1.3.0 ~1.2 := >=1.2.0 <1.(2+1).0 := >=1.2.0 <1.3.0 (Same as 1.2.x) ~1 := >=1.0.0 <(1+1).0.0 := >=1.0.0 <2.0.0 (Same as 1.x) ~0.2.3 := >=0.2.3 <0.(2+1).0 := >=0.2.3 <0.3.0 ~0.2 := >=0.2.0 <0.(2+1).0 := >=0.2.0 <0.3.0 (Same as 0.2.x) ~0 := >=0.0.0 <(0+1).0.0 := >=0.0.0 <1.0.0 (Same as 0.x) ~1.2.3-beta.2 := >=1.2.3-beta.2 <1.3.0 Note that prereleases in the 1.2.3 version will be allowed, if they are greater than or equal to beta.2.
So, 1.2.3-beta.4 would be allowed, but 1.2.4-beta.2 would not, because it is a prerelease of a different [major, minor, patch] tuple.
- ^version
Allows changes that do not modify the left-most non-zero digit in the [major, minor, patch] tuple. In other words, this allows patch and minor updates for versions 1.0.0 and above, patch updates for versions 0.X >=0.1.0, and no updates for versions 0.0.X. Many authors treat a 0.x version as if the x were the major "breaking-change" indicator. Caret ranges are ideal when an author may make breaking changes between 0.2.4 and 0.3.0 releases, which is a common practice. However, it presumes that there will not be breaking changes between 0.2.4 and 0.2.5. It allows for changes that are presumed to be additive (but non-breaking), according to commonly observed practices. ^1.2.3 := >=1.2.3 <2.0.0 ^0.2.3 := >=0.2.3 <0.3.0 ^0.0.3 := >=0.0.3 <0.0.4 ^1.2.3-beta.2 := >=1.2.3-beta.2 <2.0.0 Note that prereleases in the 1.2.3 version will be allowed, if they are greater than or equal to beta.2. So, 1.2.3-beta.4 would be allowed, but 1.2.4-beta.2 would not, because it is a prerelease of a different [major, minor, patch] tuple. ^0.0.3-beta := >=0.0.3-beta <0.0.4 Note that prereleases in the 0.0.3 version only will be allowed, if they are greater than or equal to beta. So, 0.0.3-pr.2 would be allowed. When parsing caret ranges, a missing patch value desugars to the number 0, but will allow flexibility within that value, even if the major and minor versions are both 0. ^1.2.x := >=1.2.0 <2.0.0 ^0.0.x := >=0.0.0 <0.1.0 ^0.0 := >=0.0.0 <0.1.0 A missing minor and patch values will desugar to zero, but also allow flexibility within those values, even if the major version is zero. ^1.x := >=1.0.0 <2.0.0 ^0.x := >=0.0.0 <1.0.0
- * 匹配任何版本
- “” 匹配任何版本
version1 - version2类似于>=version1 <=version2range1 || range2版本要么满足range1或者range2- URL地址放置在一个版本范围的位置处提供指定的模块，在安装时会被下载并且被安装到本地的包中
- 本地路径作为模块的指定位置，不过在发布到公共仓库时不能使用本地路径