Task 'helloworld' not found in root project while running gradle task

Question

getting below error while running from command prompt as gradle helloWorld

FAILURE: Build failed with an exception.

• What went wrong: Task 'helloWorld' not found in root project 'sample'.

• Try: Run gradle tasks to get a list of available tasks. Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output .

BUILD FAILED

Below is my build.gradle file : task helloWorld << { println 'hello, world' }

Also I am running the command from the same directory where build.gradle file exists