js-optional

Optional Class like Java 8 java.util.Optional

Install

npm install js-optional

test

npm install mocha -g

cd $JS-OPTIONAL/test

mocha test.js

Common use cases

let version = Optional.ofNullable("3.0.0").orElse("defalut");

version = Optional.ofNullable({version: "3.0.0"})
                    .flatMap(value => Optional.ofNullable(value.version))
                    .map(_ => _)
                    .orElse("UNKNOWN");

let isUSB3 = Optional.ofNullable("2.0")
                    .filter(_ => _ === "3.0")
                    .isPresent();