NPM install --global --save --save dev differences

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npm install --global <XXX>

• The effect is equivalent to npm install -g <XXX>
• overall situation Install the module
• Can't Record module dependencies in dependencies or devDependencies In the object
• function npm install When initializing a project Can't Download module

For example, I run the following code in any directory ：

npm install --global cowsay

Wrong report , It doesn't matter , This is mine npm Installed in the default directory , No access . I run it again with administrator privileges , Just fine ：

After installed , In any directory throughout the computer , I can use this module , For example, enter a command , The returned information is as follows ：

cowsay  Pangao's station 

npm install --save <XXX>

• The effect is equivalent to npm install -S <XXX>
• On the node_modules Install the module below
• stay package.json In the document dependencies Object to create a property , Used to record added dependencies
• function npm install When initializing a project , The module will be downloaded to the project node_modules Next
• function npm install --production The module will be automatically downloaded to the project node_modules Next

For example, I am in test1 Run the following code under the directory ：

cd test1

npm install --save cowsay

The results are as follows ：

npm install --save-dev <XXX>

• The effect is equivalent to npm install -D <XXX>
• On the node_modules Install the module below
• stay package.json In the document dependencies Object to create a property , Used to record added dependencies
• function npm install When initializing a project , The module will be downloaded to the project node_modules Next
• function npm install --production Can't Automatically download modules to the project node_modules Next

For example, I am in test2 Run the following code under the directory ：

cd test2

npm install --save-dev cowsay

The results are as follows ：

npm install <XXX>

• stay npm 5.0 And later on , Effect and npm install --save <XXX> As like as two peas
• stay npm 5.0 In previous versions ,npm install <XXX> The module will be downloaded to the specified project , also Can't stay package.json Document dependencies

For example, I am in test3 Run the following code under the directory ：

cd test3

npm install cowsay

The results are as follows ：

npm install And npm i The difference between

• use npm i The installed module cannot be used npm uninstall Delete , Must use npm uninstall i Just uninstall
• npm i Will help detect current node The version best matches npm Package version number , And match the interdependent npm The version number that the package should be upgraded
• part npm Package in the current node You can't use , The recommended version must be used
• When the installation reports an error intall There must be npm-debug.log file ,npm i not always

therefore , It is recommended to use npm install install , Instead of npm i install .

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