A study note page about Java objects, strings, Scanner, chars, and printf formatting, emphasizing object basics, immutability and equals(), input with Scanner, char usage, and formatted output.

<p><strong>Difficulty: Intermediate | Prerequisites: Java Fundamentals, Methods and Parameters study notes</strong></p><h2>Big Picture</h2><p>Up to this point, most of what you have worked with are primitive types and static methods. This is where Java's object-oriented nature starts to show. Objects combine state (data) and behaviour (methods) into a single unit. Strings are the most common object you will use, and they come with their own rules, especially immutability and the need to compare them with <code>.equals()</code> rather than <code>==</code>. The <code>Scanner</code> class is how your programs read user input. Characters (<code>char</code>) bridge the gap between primitives and strings. Formatted output with <code>printf</code> gives you precise control over how results are displayed. If you have fallen behind, make sure you a…</p>