String Objects: Concatenation, Literals, and More

Sophie Anderson
3 min read
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Study Guide Overview
This guide reviews string manipulation in Java for the AP Computer Science A exam. It covers strings as objects, string creation (using literals and constructors), string immutability, and essential String methods.
AP Computer Science A: String Manipulation - The Night Before ๐
Hey, future AP Computer Science ace! Let's get those strings under control. This guide is designed to be your quick, effective review, perfect for the night before the exam. We'll focus on what's crucial, keep it engaging, and make sure you're feeling confident. Let's dive in!
String Fundamentals
Strings as Objects
Did you know that strings in Java are actually objects? They belong to the String
class, which comes with a bunch of handy methods. This means strings aren't just simple text; they're powerful tools for manipulating text! Let's see how we can create them.
Creating Strings
There are two main ways to create strings:
- Pre-initialized Strings: The most common way, using double quotes.
String message = "Hello, AP CS!";
- String Constructor: Using the
new
keyword to create a new String object.String anotherMessage = new String("Hello, again!");
While both methods create strings, pre-initialized strings are often more efficient because Java can reuse them. The constructor always creates a new object in memory.
Memory Aid: String Creation
Think of it like this:
String message = "Text";
is like using a sticky note with pre-written text. It's quick and easy.String message = new String("Text");
is like making a copy of the text each time, which takes more effort.

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Question 1 of 12
In Java, what type of entity are strings considered? ๐ค
Primitive data types
Objects
Arrays
Methods