=> - Pine Script Syntax

Overview

The => token separates a user-defined function header from its body. It is also used between a switch case and the case’s local block or expression.

Function syntax

functionName(parameter1, parameter2) =>
    localBlock
    returnExpression

The last expression in the function body becomes its return value.

Example

//@version=6
indicator("Function declaration example")

average(float first, float second) =>
    float sum = first + second
    sum / 2

plot(average(open, close), "Average price")

Switch case

string sessionLabel = switch
    session.isfirstbar => "Session open"
    session.islastbar  => "Session close"
    => "Regular bar"

Remarks

• Multiline function bodies must be indented consistently.
• User-defined functions cannot be nested inside other functions.
• A function’s return type depends on its final expression and the types and qualifiers used in the call.