JavaScript Pipeline Operator

The JavaScript Pipeline Operator (|>) is used for passing the result of one expression into a function. It's particularly useful for making long chains of functions easier to read. With this operator, the value before it gets sent as input to the function that follows. You simply arrange the functions in the order you want them to act on the input.

Syntax:

expression |> function

Using the Pipeline Operator

As the Pipeline Operator is an experimental feature and currently in stage 1 proposal, there is no support for currently available browsers and therefore is also not included in Node. However, one can use Babel (JavaScript Compiler) to use it.

Steps:

• Before moving ahead, make sure that Node.js is installed.
• Create a directory on your desktop (say pipeline-operator) and within that directory create a JavaScript file (say main.js).
• Navigate to the directory and initialize a package.json file that contains relevant information about the project and its dependencies. 

  npm init

• Install Babel in order to use the operator. A pipeline operator is not currently part of JavaScript language, babel is used to compile the code so that it can be understood by Node.

  npm install @babel/cli @babel/core 
   @babel/plugin-proposal-pipeline-operator 

• To direct Babel about the compilation of the code properly, a file named .babelrc is created with the following lines:

  {
   "plugins": 
   [
   [
   "@ babel/plugin-proposal-pipeline-operator",
   {
   "proposal" : "minimal"
   } 
   ]
   ]
  }

• Add a start script to the package.json file which will run babel:

  "start" : "babel main.js --out-file output.js && node output.js"

• Run the code: 

  npm start

Example: This exmaple shows the use of Pipeline Operator.

Output:

20
20