Five platforms profiled for a new coder — what makes a platform good for a beginner, what each one is best for, how to pick one by your goal, and a simple weekly routine to build skill steadily.

Knowing Java is not the same as answering for it under pressure. This guide works through the questions panels keep returning to — strings, HashMaps, OOP and memory — with runnable code and the reasoning behind each answer.

Textbook definitions make OOP sound harder than it is — the ideas come from everyday life. Classes are blueprints, bank accounts explain encapsulation, and a single word like 'cut' shows polymorphism, all with Java code to match.

Lists and strings carry almost every beginner coding task — and most interview questions too. Fifteen worked problems, from finding a largest element to anagrams and string compression, each with an explanation and its time complexity.

Service-based recruiters test a small, predictable set of topics — not the advanced algorithms students fear. This guide ranks the ones that actually appear, from arrays and strings to linked lists and hashing, with a frequency table and a focused practice plan.