Java Special Characters: Escaping, Unicode, and Text Blocks

1. Escape Sequences in Java Strings

Java uses backslashes (\) to escape characters with special meanings.

Common Escape Characters

Escape	Meaning	Example	Output
`\n`	Newline	`"Line1\nLine2"`	Line1 Line2
`\t`	Tab	`"Name:\tAlice"`	Name: Alice
`\"`	Double Quote	`"She said \"Hi\""`	She said “Hi”
`\\`	Backslash	`"C:\\Users\\"`	C:\Users\
`\'`	Single Quote	`'Don\'t stop'`	Don’t stop

Example:

String json = "{ \"name\": \"Alice\", \"age\": 30 }";  
System.out.println(json);  
// Output: { "name": "Alice", "age": 30 }

2. Unicode Characters

Java supports Unicode via \u followed by a 4-digit hex code.

Using Unicode in Strings

String copyright = "Copyright \u00A9 2024";  // © symbol  
String heart = "I \u2764 Java!";             // ❤ symbol

Key Notes:

Unicode works for any character, including emojis: \uD83D\uDE00 (😀).
Use hex values from Unicode charts.

3. Text Blocks (Java 15+)

Text blocks (""") simplify writing multi-line strings without escape characters.

Traditional vs. Text Block

// Old approach (messy):  
String html = "<html>\n" +  
              "  <body>\n" +  
              "    <p>Hello</p>\n" +  
              "  </body>\n" +  
              "</html>";  

// Text block (clean):  
String htmlBlock = """  
                  <html>  
                    <body>  
                      <p>Hello</p>  
                    </body>  
                  </html>  
                  """;

Text Block Rules

Start/end with """ on separate lines.
Indentation is removed based on the closing """ position.
Escape """ inside with \""".

4. Handling Edge Cases

Escaping in Text Blocks

Use \ to suppress line breaks or escape delimiters:

String poem = """  
              Roses are red,\  
              Violets are blue.\  
              Java is awesome,\  
              And so are you!  
              """;  
// Output: Roses are red, Violets are blue. Java is awesome, And so are you!

Mixing Quotes

Text blocks handle quotes without escaping:

String sql = """  
             SELECT * FROM users  
             WHERE name = "Alice"  
             """;

Common Mistakes

❌ Forgetting to Escape Backslashes:

String path = "C:\Users\file.txt";  // Error!  
String path = "C:\\Users\\file.txt";  // ✅

❌ Incorrect Unicode Syntax:

String error = "\u00G1";  // Invalid hex 'G' → compile error  
String correct = "\u00F1";  // ñ

❌ Text Block Alignment Issues:

// Misaligned closing """ adds unintended spaces:  
String s = """  
           Hello  
           """;  // "Hello\n" (no trailing space)

FAQ

How to write a Windows file path without escaping?

Use text blocks (Java 15+) or replace \ with /:
String path = """ C:\Users\Alice\file.txt """; // Backslashes allowed in text blocks!

Can I use text blocks for short strings?

Yes, but they’re best for multi-line content (JSON/HTML).

What Java versions support text blocks?

Standardized in Java 15 (preview in 13 and 14).