1 Java Language Changes Summary

The following tables summarize new Java language features since Java SE 9.

New Language Features

The following table lists the new features in the Java language since Java SE 9.

Table 1-1 Java Language Changes Summary

Release	New Language Features
9	Java Platform Module System (JSR 376): see Project Jigsaw on OpenJDK Milling Project Coin (JEP 213): see Java Language Changes for Java SE 9 Small Enhancements to the Java Programming Language (JSR 334): see Java Language Changes for Java SE 9
10	Local Variable Type Inference (JEP 286)
11	Local-Variable Syntax for Lambda Parameters (JEP 323): see Local Variable Type Inference
14	Switch Expressions and Statements (JEP 361)
15	Text Blocks (JEP 378)
16	Record Classes (JEP 395) Pattern Matching with instanceof (JEP 394)
17	Sealed Classes (JEP 409)
21	Record Patterns (JEP 440) Pattern Matching with switch (JEP 441)
22	Unnamed Variables and Patterns (JEP 456)
25	Module Import Declarations (JEP 511) Compact Source Files and Instance main Methods (JEP 512) Flexible Constructor Bodies (JEP 513)

Permanent and Preview Language Features

The following table lists, for each release since Java SE 9, which language features became permanent and which language features were in preview. See Preview Features for information about preview features and how they can become permanent.

Table 1-2 Java Language Changes Summary

Release	Permanent Features	Preview Features
25	Module Import Declarations (JEP 511) Compact Source Files and Instance main Methods (JEP 512) Flexible Constructor Bodies (JEP 513)	Primitive Types in Patterns, instanceof, and switch (JEP 507): see: When Clauses Type Patterns with Primitive Types Primitive Types in Record Patterns Primitive Values in switch Expressions and Statements Safe Casting with instanceof and switch
24		Module Import Statements (JEP 494) Primitive Types in Patterns, instanceof, and switch (JEP 488): see: When Clauses Type Patterns with Primitive Types Primitive Types in Record Patterns Primitive Values in switch Expressions and Statements Safe Casting with instanceof and switch Flexible Constructor Bodies (JEP 482) Simple Source Files and Instance Main Methods (JEP 495)
23		Module Import Declarations (JEP 476) Primitive Types in Patterns, instanceof, and switch (JEP 455): see: Implicitly Declared Classes and Instance Main Methods (JEP 477) Flexible Constructor Bodies (JEP 482)
22	Unnamed Variables and Patterns (JEP 456)	Statements Before super(...) (JEP 447) String Templates (JEP 459) Implicitly Declared Classes and Instance Main Methods (JEP 463)
21	Record Patterns (JEP 440) Pattern Matching with switch (JEP 441)	String Templates (JEP 430) Unnamed Patterns and Variables (JEP 443) Unnamed Classes and Instance Main Methods (JEP 445)
20		Pattern Matching for switch Expressions and Statements (JEP 433) Record Patterns (JEP 432)
19		Pattern Matching for switch Expressions and Statements (JEP 427) Record Patterns (JEP 405)
18		Pattern Matching for switch Expressions and Statements (JEP 420)
17	Sealed Classes (JEP 409)	Pattern Matching for switch Expressions and Statements (JEP 406)
16	Record Classes (JEP 395) Pattern Matching with instanceof (JEP 394)	Sealed Classes (JEP 397)
15	Text Blocks (JEP 378)	Sealed Classes (JEP 36) Record Classes (JEP 384) Pattern Matching for instanceof (JEP 375)
14	Switch Expressions and Statements (JEP 361)	Pattern Matching for the instanceof Operator (JEP 305) Records (JEP 359) Text Blocks (JEP 368)
13		Text Blocks (JEP 355), see Programmer's Guide to Text Blocks Switch Expressions (JEP 354)
12		Switch Expressions (JEP 325)
11	Local-Variable Syntax for Lambda Parameters (JEP 323): see Local Variable Type Inference
10	Local Variable Type Inference (JEP 286)
9	Java Platform Module System (JSR 376): see Project Jigsaw on OpenJDK Milling Project Coin (JEP 213): see Java Language Changes for Java SE 9 Small Enhancements to the Java Programming Language (JSR 334): see Java Language Changes for Java SE 9

Evolution of Language Features

The following tables list the changes made to the Java language since Java SE 9. The first column specifies the feature while the subsequent columns specify a Java SE release. An icon specifies whether the feature was made permanent, withdrawn for the specified release, or available as a preview feature:

• : Permanent feature
• : The feature was withdrawn
• , , , : First, second, third, or fourth preview, respectively

See Preview Features for information about preview features and how they can become permanent or be withdrawn.

Table 1-3 Java Language Changes in Java SE 25

Feature	25
Module Import Declarations	JEP 511
Primitive Types in Patterns, instanceof, and switch	JEP 507
Flexible Constructor Bodies	JEP 513
Compact Source Files and Instance main Methods	JEP 512

Table 1-4 Java Language Changes from Java SE 24 to Java SE 17

Feature	24	23	22	21	20	19	18	17
Module Import Declarations	JEP 494	JEP 476
Primitive Types in Patterns, instanceof, and switch	JEP 488	JEP 455
Flexible Constructor Bodies	JEP 492	JEP 482	JEP 447
Simple Source Files and Instance Main Methods	JEP 495	JEP 477	JEP 463	JEP 445
Unnamed Variables and Patterns			JEP 456	JEP 443
String Templates			JEP 459	JEP 430
Record Patterns				JEP 440	JEP 432	JEP 405
Pattern Matching with switch				JEP 441	JEP 433	JEP 427	JEP 420	JEP 406
Sealed Classes								JEP 409

Table 1-5 Java Language Changes from Java SE 16 to Java SE 9

Feature	16	15	14	13	12	11	10	9
Sealed Classes	JEP 397	JEP 360
Record Classes	JEP 395	JEP 384	JEP 359
Pattern Matching with instanceof	JEP 394	JEP 375	JEP 305
Text Blocks		JEP 378	JEP 368	JEP 355
Switch Expressions and Statements			JEP 361	JEP 354	JEP 325
Local-Variable Syntax for Lambda Parameters: see Local Variable Type Inference						JEP 323
Local Variable Type Inference							JEP 286
Java Platform Module System: see Project Jigsaw on OpenJDK								JSR 376
Milling Project Coin: see Java Language Changes for Java SE 9								JEP 213
Small Enhancements to the Java Programming Language: see Java Language Changes for Java SE 9								JSR 334