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Labs/JavaScript/Data Structure

Intermediate LevelDATA STRUCTURES · JavaScript TrackCompiler: node 20.x (V8 Engine)

JavaScript Data Structures & Collections

Template literals, array transformation methods (map/filter), and Map/Set.

Exercises:1 Practice Labs

All JavaScript Modules

Switch Module:Basic (5)Functions (2)Data Structure (3)OOP (1)Async & Runtime (1)

Data Structure Coding Labs (1)Click any card to start in laboratory

Lab #01 · Strings & Slicing

08. String Slicing, Methods & Masking

Sanitize strings and mask sensitive data using `.slice()`.

Objective: Write a function `maskApiKey(key)` that displays only the first 4 and last 4 characters, replacing the middle with `****`.

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