CompletableFuture runAsync vs supplyAsync, when to choose one over the other?

runAsync takes Runnable as input parameter and returns CompletableFuture<Void>, which means it does not return any result.

CompletableFuture<Void> run = CompletableFuture.runAsync(()-> System.out.println("hello"));

But suppyAsync takes Supplier as argument and returns the CompletableFuture<U> with result value, which means it does not take any input parameters but it returns result as output.

CompletableFuture<String> supply = CompletableFuture.supplyAsync(() -> {
        System.out.println("Hello");
        return "result";
    });

 System.out.println(supply.get());  //result

Conclusion : So if you want the result to be returned, then choose supplyAsync or if you just want to run an async action, then choose runAsync.