Syntax Lookup

Enter some language construct you want to know more about.

This is a placeholder.

Placeholders may be used for ignoring parts of values (including serving as a catch-all in switch statements), and specifying the position of an argument.

Example: Ignoring values

ReScriptJS Output

switch person1 {
| Teacher(_) => Console.log("Hi teacher")
| Student(_) => Console.log("Hey student")
}

Example: Specifying an argument position

ReScriptJS Output

let greet = (greeting, name) => greeting ++ " " ++ name

// Pipe the value "John" into the second argument of the greet() function.
let greetJohn = "John"->greet("Hello", _)

References