| pattern | description |
|---|---|
| . | any character except a newline |
| ^ | start of the string |
| $ | end of the string |
| * | match 0 or more repetitions of the preceding RE. greedy. |
| + | match 1 or more repetitions of the preceding RE. greedy. |
| ? | match 0 or 1 repetitions of the preceding RE. greedy. |
| *? | non-greedy version of * |
| +? | non-greedy version of + |
| ?? | non-greedy version of ? |
| {m} | exactly m copies of the previous RE |
| {m,n} | match from m to n repetitions of the precedingRE |
| {m,n}? | non-greedy version of {m ,n} |
| \ | escapes special characters |
| [] | indicate a set of characters |
| | | match either A or B, where A and B can be arbitrary REs |
greedy: they match as much text as possiblenon-greedy: minimal fashion; as few characters as possible will be matched
iThome鐵人賽
看影片追技術