jung gyu yoon's HackerRank Certificates
Certificate: Ruby (Intermediate)
skill
Certificate: Python (Basic)
skill
Certificate: Java (Basic)
skill
Certificate: Ruby (Basic)
skill
Certificate: Python (Intermediate)
skill
Certificate: Python (Advanced)
skill
Certificate: Problem Solving (Intermediate)
skill
Certificate: Problem Solving (Basic)
skill
Certificate: Java (Intermediate)
skill
Certificate: C++ (Basic)
skill
Certificate: C++ (Intermediate)
skill
Certificate: SQL (Basic)
skill
Certificate: C (Basic)
skill
Certificate: C (Intermediate)
skill
Ruby (Intermediate)
It covers topics like Ruby Built-ins, Hash, Range, Set, Collections and Enumerables, simple regular expressions, reading, and writing to JSON and XML file types, among others