Java Language Changes Summary

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): seeJava 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 (JEP 361)
15	Text Blocks (JEP 378)
16	Record Classes (JEP 395) Pattern Matching for the instanceof Operator (JEP 394)
17	Sealed Classes (JEP 409)
21	Record Patterns (JEP 440) Pattern Matching for switch Expressions and Statements (JEP 441)

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
21	Record Patterns (JEP 440) Pattern Matching for switch Expressions and Statements (JEP 441)	String Templates Unnamed Patterns and Variables Unnamed Classes and Instance Main Methods
20		Pattern Matching for switch Expressions and Statements Record Patterns
19		Pattern Matching for switch Expressions and Statements Record Patterns
18		Pattern Matching for switch Expressions and Statements
17	Sealed Classes (JEP 409)	Pattern Matching for switch Expressions and Statements
16	Record Classes (JEP 395) Pattern Matching for the instanceof Operator (JEP 394	Sealed Classes
15	Text Blocks (JEP 378)	Sealed Classes Record Classes Pattern Matching for instanceof
14	Switch Expressions (JEP 361)	Pattern Matching for the instanceof Operator Records Text Blocks
13		Text Blocks, see Programmer's Guide to Text Blocks Switch Expressions
12		Switch Expressions
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 or available as a preview feature:

: Permanent feature
, , , : 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 from Java SE 21 to Java SE 17

Feature	21	20	19	18	17
Simple Source Files and Instance Main Methods	JEP 445
Unnamed Patterns and Variables	JEP 443
String Templates	JEP 430
Record Patterns	JEP 440	JEP 432	JEP 405
Pattern Matching for switch Expressions and Statements	JEP 441	JEP 433	JEP 427	JEP 420	JEP 406
Sealed Classes					JEP 409

Table 1-4 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 for the instanceof Operator	JEP 394	JEP 375	JEP 305
Text Blocks		JEP 378	JEP 368	JEP 355
Switch Expressions			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