Get the most from each lesson's compiled editor—the same habits that transfer to VS Code, GoLand, and CI running go test.
Recommended workflow
- Read the concept section before editing code.
- Click Run to compile with
go runand execute. - Use
fmt.Printlnandfmt.Printffor debug output. - Change one idea at a time; read compiler errors from top to bottom.
What the runner can and cannot do
- Can — single-file
package mainwith the standard library - Needs local setup — multi-module workspaces, long-running HTTP servers, Kubernetes clients
Review Python, Java, and Rust for comparison context.
Important interview questions and answers
- Q: What package prints to stdout in Go lessons?
A:fmt—fmt.Printlnandfmt.Printf. - Q: What is the entry point of a Go program?
A:func main()in packagemain.
Self-check
- What package provides Println?
- What is the first step when the compiler rejects your code?
Challenge
First compile and run
- Click Run with the default code.
- Confirm output appears in the terminal.
- Add a second
fmt.Printlnwith your name.
Done when: the terminal shows the default message and your custom line.
Challenge
Verify go run output
- Run the default program.
- Confirm output in the terminal.
- Add a deliberate syntax error and read the compiler message.
- Fix and run again.
Done when: you see compiler errors when appropriate and clean output after fixing.
Interview prep
- What runs code in the playground?
go runcompiles and executes a single main.go with package main and func main().