Pipeline operator (|>)

The experimental pipeline operator |> (currently at stage 1) pipes the value of an expression into a function. This allows the creation of chained function calls in a readable manner. The result is syntactic sugar in which a function call with a single argument can be written like this:

let url = "%21" |> decodeURI;

The equivalent call in traditional syntax looks like this:

let url = decodeURI("%21");

Syntax

expression |> function

The value of the specified expression is passed into the function as its sole parameter.

Parameters

expression
Any valid expression.
function
Any function.

Examples

Chaining function calls

The pipeline operator can improve readability when chaining several functions.

const double = (n) => n * 2;
const increment = (n) => n + 1;

// without pipeline operator
double(increment(double(double(5)))); // 42

// with pipeline operator
5 |> double |> double |> increment |> double; // 42

Specifications

Specification
Pipeline operator
The definition of 'Pipeline operator' in that specification.

Browser compatibility

DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
Pipeline operator (|>)
Experimental
Chrome No support NoEdge No support NoFirefox No support NoIE No support NoOpera No support NoSafari No support NoWebView Android No support NoChrome Android No support NoFirefox Android No support NoOpera Android No support NoSafari iOS No support NoSamsung Internet Android No support Nonodejs No support No

Legend

No support
No support
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.

See also