https://google.github.io/styleguide/javaguide.html#s2.3.2-special-escape-sequences
2.3.2 Special escape sequences
For any character that has a special escape sequence (\b, \t, \n, \f, \r, \s, ", ' and \), that sequence is used rather than the corresponding octal (e.g. \012) or Unicode (e.g. \u000a) escape.
I have read check documentation: https://checkstyle.org/checks/coding/illegaltokentext.html
I have downloaded the latest checkstyle from: https://checkstyle.org/cmdline.html#Download_and_Run
I have executed the cli and showed it below, as cli describes the problem better than 1,000 words
Code:
$ cat EscapedCodes.java
class EscapedCodes {
public void unicode() {
final String r0 = "\s";
final String r1 = "\u000b"; // Expected violation
final String r2 = "\u000c"; // OK
final String r3 = "\u001c"; // Expected violation
final String r4 = "\u001D"; // Expected violation
final String r5 = "\u001E"; // Expected violation
final String r6 = "\u001F"; // Expected violation
final String r7 = "\u1680"; // Expected violation
final String r8 = "\u2000"; // Expected violation
final String r9 = "\u200A"; // Expected violation
final String r10 = "\u2028"; // Expected violation
final String r12 = "\u2029"; // Expected violation
final String r13 = "\u202F"; // Expected violation
final String r14 = "\u205F"; // Expected violation
final String r15 = "\u3000"; // Expected violation
}
public void octal() {
final String r1 = "\040"; // Expected violation
final String r2 = "\011"; // ok
final String r3 = "\012"; // ok
}
}Cli:
$ java -jar checkstyle-10.26.1-all.jar -c google_checks.xml EscapedCodes.java
Starting audit...
[WARN] /mnt/5D92528E6B945467/test/testing/EscapedCodes.java:5:23: Consider using special escape sequence instead of octal value or Unicode escaped value. [IllegalTokenText]
[WARN] /mnt/5D92528E6B945467/test/testing/EscapedCodes.java:22:23: Consider using special escape sequence instead of octal value or Unicode escaped value. [IllegalTokenText]
[WARN] /mnt/5D92528E6B945467/test/testing/EscapedCodes.java:23:23: Consider using special escape sequence instead of octal value or Unicode escaped value. [IllegalTokenText]
Audit done.
https://en.wikipedia.org/wiki/Whitespace_character
For example, a space character (U+0020 SPACE, ASCII 32) represents blank space such as a word divider in a Western script.
The 040 part is the octal (base-8) representation of the ASCII code for the space character, which is decimal 32.
https://google.github.io/styleguide/javaguide.html#s2.3.2-special-escape-sequences
I have read check documentation: https://checkstyle.org/checks/coding/illegaltokentext.html
I have downloaded the latest checkstyle from: https://checkstyle.org/cmdline.html#Download_and_Run
I have executed the cli and showed it below, as cli describes the problem better than 1,000 words
Code:
Cli:
https://en.wikipedia.org/wiki/Whitespace_character
The 040 part is the octal (base-8) representation of the ASCII code for the space character, which is decimal 32.