差異處
這裏顯示兩個版本的差異處。
| 下次修改 | 前次修改 | ||
|
java:java_regular_expression [2017/09/27 22:36] tony 建立 |
java:java_regular_expression [2023/06/25 09:48] (目前版本) |
||
|---|---|---|---|
| 行 6: | 行 6: | ||
| <code java> | <code java> | ||
| @Test | @Test | ||
| - | public void testPattern(){ | + | public void testPatternWithoutDotAll(){ |
| Pattern p = Pattern.compile("test.*"); | Pattern p = Pattern.compile("test.*"); | ||
| Matcher m = p.matcher("test 123\n456"); | Matcher m = p.matcher("test 123\n456"); | ||
| 行 23: | 行 23: | ||
| } | } | ||
| </code> | </code> | ||
| + | ==== 為何square只能用在第一行? ==== | ||
| + | 我想找開頭為test的那行，我使用以下的pattern: | ||
| + | <code java> | ||
| + | @Test | ||
| + | public void testPatternWithSqure(){ | ||
| + | Pattern p = Pattern.compile("^test.*"); | ||
| + | Matcher m = p.matcher("abc\ntest123\n567"); | ||
| + | assertTrue(m.find()); | ||
| + | assertEquals("test123", m.group()); | ||
| + | } | ||
| + | </code> | ||
| + | 執行後會test failed，但test在第一行卻會很正常；最後[[https://stackoverflow.com/questions/44922041/why-is-the-beginning-of-a-line-not-recognized-by-a-regex|爬文]]得知，要搭配Pattern.MULTILINE一起使用: | ||
| + | <code java> | ||
| + | @Test | ||
| + | public void testPatternWithSqure(){ | ||
| + | Pattern p = Pattern.compile("^test.*", Pattern.MULTILINE); | ||
| + | // 略過 | ||
| + | } | ||
| + | </code> | ||
| ===== Resource ===== | ===== Resource ===== | ||
| * [[https://docs.oracle.com/javase/8/docs/api/java/util/regex/Pattern.html|Javadoc - Pattern]] | * [[https://docs.oracle.com/javase/8/docs/api/java/util/regex/Pattern.html|Javadoc - Pattern]] | ||
| - | + | ===== ===== | |
| - | + | ---- | |
| + | \\ | ||
| + | ~~DISQUS~~ | ||
