Java String Methods

What You’ll Find Here

The java.lang.String class provides dozens of methods for reading characters, comparing text, searching substrings, joining strings, formatting output, and encoding bytes. This page is your central hub: browse every method in our tutorial series, jump to full guides with examples and output, and learn patterns that work in real Java programs.

Introduction

In Java, strings are objects of type String. You call methods with dot notation: text.charAt(0), name.equals("Java"), file.endsWith(".java"). A few helpers are static and live on the class itself: String.format(...) and String.copyValueOf(...).

Strings are immutable—once created, their characters cannot change. Methods like concat() and toUpperCase() return new String objects rather than modifying the original.

🚀 Usage Tips

• Use equals() for text — never compare string content with == unless you mean reference equality.
• Null-safe equals — write "expected".equals(variable) when variable may be null.
• Pick the right search — contains() for presence, endsWith() for suffixes, indexOf() when you need the position.
• Prefer UTF-8 — use getBytes(StandardCharsets.UTF_8) instead of the no-arg form for portable encoding.
• Static vs instance — format() and copyValueOf() are static; most other methods are called on a String variable.
• Read the tutorial — each linked method page includes syntax, five examples, a quick reference table, and FAQs.

📝 How to Call a String Method

Most String methods follow this pattern:

stringReference.methodName(arguments)

Common Patterns

Instance Methods vs Static Methods

Most String methods run on an existing string object. Static methods belong to the String class and do not require a particular string instance to start with.

String greeting = "Hello";
char first = greeting.charAt(0);              // instance: read character
boolean match = greeting.equals("Hello");     // instance: compare content
String joined = greeting.concat(", Java!");   // instance: join text

String formatted = String.format("Count: %d", 42);     // static: template
String fromArray = String.copyValueOf(new char[]{'J','a','v','a'}); // static