Entering Non-Printable Characters
Problem
You need to put non-printable characters into strings.
Solution
Use the backslash character and one of the Java string escapes.
Discussion
The Java string escapes are listed in Table 3-1.
Table 3-1. String escapes
To get: |
Use this: |
Notes |
---|---|---|
Tab |
| |
Linefeed (Unix newline) |
|
See |
Carriage return |
| |
Form feed |
| |
Backspace |
| |
Single quote |
| |
Double quote |
| |
Unicode character |
|
Four hexadecimal digits (no |
Octal(!) character |
|
Who uses octal (base 8) these days? |
Backslash |
|
Here is a code example that shows most of these in action:
// StringEscapes.java System.out.println("Java Strings in action:"); // System.out.println("An alarm or alert: \a"); // not supported System.out.println("An alarm entered in Octal: \007"); System.out.println("A tab key: \t(what comes after)"); System.out.println("A newline: \n(what comes after)"); System.out.println("A UniCode character: \u0207"); System.out.println("A backslash character: \\");
If you have a lot of non-ASCII characters to enter, you may wish to consider using Java’s input methods, discussed briefly in the JDK online documentation.
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