Challenge Library
Coding Challenges
5,893 curated questions across every arena — browse by topic, then jump into a live 2-minute battle to put them to the test.
Filter by type
Filter by difficulty
Popular topics
2,721 challenges matching your filters
- Code AnalysisIntermediate
Trace: Slice #35
goanalysisintermediate - Code AnalysisIntermediate
Trace: Slice #36
goanalysisintermediate - Code AnalysisIntermediate
Trace: Slice #37
goanalysisintermediate - Code AnalysisIntermediate
Trace: Slice #38
goanalysisintermediate - Code AnalysisIntermediate
Trace: Slice #39
goanalysisintermediate - Code AnalysisIntermediate
Trace: Slice #40
goanalysisintermediate - Code AnalysisIntermediate
Trace: Slice #41
goanalysisintermediate - Code AnalysisIntermediate
Trace: Slice #42
goanalysisintermediate - Multiple ChoiceIntermediate
Go: Concurrency
gointermediate - Multiple ChoiceIntermediate
Go: Interfaces
gointermediate - Multiple ChoiceIntermediate
Go: Slice Capacity
gointermediate - Multiple ChoiceIntermediate
Go: Slice Slicing
gointermediate - Multiple ChoiceIntermediate
Go: Copy Slice
gointermediate - Multiple ChoiceIntermediate
Go: Map Lookup
gointermediate - Multiple ChoiceIntermediate
Go: Delete Map
gointermediate - Multiple ChoiceIntermediate
Go: Method Receivers
gointermediate - Multiple ChoiceIntermediate
Go: Pointer Receiver
gointermediate - Multiple ChoiceIntermediate
Go: Interface Satisfaction
gointermediate - Multiple ChoiceIntermediate
Go: Type Assertion — Comma-ok
gointermediate - Multiple ChoiceIntermediate
Go: Type Switch — Interface Dispatch
gointermediate - Multiple ChoiceIntermediate
Go: Error Wrapping
gointermediate - Multiple ChoiceIntermediate
Go: errors.Is
gointermediate - Multiple ChoiceIntermediate
Go: errors.As
gointermediate - Multiple ChoiceIntermediate
Go: Panic — Defer Recovery
gointermediate - Multiple ChoiceIntermediate
Go: Recover — Return Value
gointermediate - Multiple ChoiceIntermediate
Go: Goroutine vs Thread
gointermediate - Multiple ChoiceIntermediate
Go: Channel Buffer
gointermediate - Multiple ChoiceIntermediate
Go: Channel Close
gointermediate - Multiple ChoiceIntermediate
Go: Range Over Channel
gointermediate - Multiple ChoiceIntermediate
Go: Select — Default Case
gointermediate - Multiple ChoiceIntermediate
Go: Select Default
gointermediate - Multiple ChoiceIntermediate
Go: sync.Mutex
gointermediate - Multiple ChoiceIntermediate
Go: sync.WaitGroup
gointermediate - Multiple ChoiceIntermediate
Go: sync.Once — Error Handling
gointermediate - Multiple ChoiceIntermediate
Go: Context — Deadline
gointermediate - Multiple ChoiceIntermediate
Go: context.WithCancel
gointermediate - Multiple ChoiceIntermediate
Go: context.WithTimeout
gointermediate - Multiple ChoiceIntermediate
Go: Embedding — Method Promotion
gointermediate - Multiple ChoiceIntermediate
Go: Promoted Methods
gointermediate - Multiple ChoiceIntermediate
Go: json.Marshal
gointermediate - Multiple ChoiceIntermediate
Go: json tags (i31)
gointermediate - Multiple ChoiceIntermediate
Go: net/http — Timeouts
gointermediate - Multiple ChoiceIntermediate
Go: http.HandleFunc
gointermediate - Multiple ChoiceIntermediate
Go: io.Reader
gointermediate - Multiple ChoiceIntermediate
Go: io.Writer
gointermediate - Multiple ChoiceIntermediate
Go: os.Open
gointermediate - Multiple ChoiceIntermediate
Go: bufio.Scanner
gointermediate - Multiple ChoiceIntermediate
Go: strconv.Itoa
gointermediate - Multiple ChoiceIntermediate
Go: strings.Contains
gointermediate - Multiple ChoiceIntermediate
Go: sort.Ints
gointermediate - Multiple ChoiceIntermediate
Go: time.Now
gointermediate - Multiple ChoiceIntermediate
Go: time.Sleep
gointermediate - Multiple ChoiceIntermediate
Go: Testing
gointermediate - Multiple ChoiceIntermediate
Go: Table Tests — Subtests
gointermediate - Multiple ChoiceIntermediate
Go: _test.go
gointermediate - Multiple ChoiceIntermediate
Go: init() — Import Order
gointermediate - Multiple ChoiceIntermediate
Go: Package Alias
gointermediate - Multiple ChoiceIntermediate
Go: Blank Import
gointermediate - Multiple ChoiceIntermediate
Go: GOPATH vs Modules
gointermediate - Multiple ChoiceIntermediate
Go: go get
gointermediate
Practice now, dominate the arena
Every challenge here is drawn from the live Code Royale pool. Review a question, then head to the arena to answer under pressure against a real opponent — 2-minute matches, Elo ranking, and badge tiers on the line.