- Python – Data Types
The types you will use every day — int, float, str, bool, None — plus what a variable really is in Python, why `is` and `==` are not the same question, and the integer division and float rounding traps that bite everyone once.
- Exception Handling
An exception is Java's way of saying "I cannot continue, and here is exactly why". Handling them well is mostly about restraint: catching only what you can actually do something about, and never hiding what you cannot. try , catch , finally The try block holds code that might fail. The catch runs…
- Collections
Collections are the containers you reach for in every program: a list of orders, a set of tags, a map from id to customer. Java gives you four shapes and several implementations of each. Picking one should take about five seconds, and this post is mostly about making that true. The four shapes…
- What a Data Structure Actually Is
A data structure is a decision about how to lay data out in memory, and an algorithm is a decision about how to walk it. Why there is no best structure, the four questions that pick one, and the Java collection each choice maps onto.
- React – State with useState
State is what a component remembers between renders. Why a plain variable will not do, the array destructuring useState returns, the rules that govern where hooks may be called, one state variable versus several, and the moment to stop and lift state up to a shared parent instead.