Challenge Library
Coding Challenges
5,893 curated questions across every arena — browse by topic, then jump into a live 3-minute battle to put them to the test.
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80 challenges matching your filters
Clear topic filter- Code AnalysisHard
Array Decay
code-analysisClanguage - Code AnalysisBeginner
Bitwise AND
code-analysisClanguage - Code AnalysisBeginner
Comma Operator
code-analysisClanguage - Code AnalysisHard
Const Cast
code-analysisClanguage - Code AnalysisHard
Dangling Pointer
code-analysisClanguage - Code AnalysisBeginner
Double to Int
code-analysisClanguage - Code AnalysisIntermediate
Macro Expansion Trap
code-analysisClanguage - Code AnalysisHard
Negative Modulo
code-analysisClanguage - Code AnalysisBeginner
Null Pointer Print
code-analysisClanguage - Code AnalysisIntermediate
Post-increment Loop
code-analysisClanguage - Code AnalysisIntermediate
Pointer Arithmetic
code-analysisClanguage - Code AnalysisHard
restrict Pointer
code-analysisClanguage - Code AnalysisHard
Shift Overflow
code-analysisClanguage - Code AnalysisHard
Struct Sizeof
code-analysisClanguage - Code AnalysisIntermediate
String Literal Length
code-analysisClanguage - Code AnalysisHard
Switch Fall-through
code-analysisClanguage - Code AnalysisIntermediate
Ternary Operator
code-analysisClanguage - Code AnalysisHard
Type Promotion
code-analysisClanguage - Code AnalysisHard
Unsigned Underflow
code-analysisClanguage - Code AnalysisHard
XOR Swap Same
code-analysisClanguage - Code AnalysisBeginner
Append to Nil Slice
code-analysisGolanguage - Code AnalysisIntermediate
Close Channel Read
code-analysisGolanguage - Code AnalysisBeginner
Copy Min
code-analysisGolanguage - Code AnalysisIntermediate
Defer LIFO
code-analysisGolanguage - Code AnalysisBeginner
For Range String
code-analysisGolanguage - Code AnalysisBeginner
Function Variable
code-analysisGolanguage - Code AnalysisHard
Goroutine Capture
code-analysisGolanguage - Code AnalysisBeginner
Interface Conversion
code-analysisGolanguage - Code AnalysisHard
Iota Math
code-analysisGolanguage - Code AnalysisBeginner
Map Comma OK
code-analysisGolanguage - Code AnalysisHard
Named Return Shadow
code-analysisGolanguage - Code AnalysisHard
Nil Interface Trap
code-analysisGolanguage - Code AnalysisBeginner
Nil Slice Len
code-analysisGolanguage - Code AnalysisHard
Panic with Defer
code-analysisGolanguage - Code AnalysisHard
Range Pointer Trap
code-analysisGolanguage - Code AnalysisBeginner
Short Var Scope
code-analysisGolanguage - Code AnalysisHard
Slice Capacity Sharing
code-analysisGolanguage - Code AnalysisBeginner
String Immutability
code-analysisGolanguage - Code AnalysisIntermediate
Switch No Expression
code-analysisGolanguage - Code AnalysisHard
Type Assert Panic
code-analysisGolanguage - Code AnalysisBeginner
Every & Some
code-analysisJavaScriptlanguage - Code AnalysisIntermediate
Async forEach
code-analysisJavaScriptlanguage - Code AnalysisBeginner
BigInt Operations
code-analysisJavaScriptlanguage - Code AnalysisIntermediate
Closure var Loop
code-analysisJavaScriptlanguage - Code AnalysisBeginner
Curried Function
code-analysisJavaScriptlanguage - Code AnalysisBeginner
Default Destructure
code-analysisJavaScriptlanguage - Code AnalysisIntermediate
Float Equality
code-analysisJavaScriptlanguage - Code AnalysisHard
IIFE Semicolon Trap
code-analysisJavaScriptlanguage - Code AnalysisIntermediate
Microtask vs Task
code-analysisJavaScriptlanguage - Code AnalysisIntermediate
null vs undefined
code-analysisJavaScriptlanguage - Code AnalysisBeginner
Nullish Coalescing
code-analysisJavaScriptlanguage - Code AnalysisBeginner
Optional Chaining
code-analysisJavaScriptlanguage - Code AnalysisBeginner
Prototype Chain
code-analysisJavaScriptlanguage - Code AnalysisHard
Proxy Trap
code-analysisJavaScriptlanguage - Code AnalysisBeginner
Sort Mutates
code-analysisJavaScriptlanguage - Code AnalysisHard
Sparse Array
code-analysisJavaScriptlanguage - Code AnalysisBeginner
Spread on String
code-analysisJavaScriptlanguage - Code AnalysisHard
String Coercion
code-analysisJavaScriptlanguage - Code AnalysisIntermediate
This Lost Binding
code-analysisJavaScriptlanguage - Code AnalysisHard
Type Coercion Madness
code-analysisJavaScriptlanguage
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