| 1. | Marks the beginning of a bracket expression
标记中括号表达式的开始。 |
| 2. | Do not confuse this use of the with the use within a bracket expression
不要将^的这种用法与中括号表达式内的用法混淆。 |
| 3. | To include the hyphen character in a bracket expression , do one of the following
若要在中括号表达式中包括连字符，请采用下列方法之一： |
| 4. | Most special characters lose their meaning when they occur inside a bracket expression
大多数特殊字符在中括号表达式内出现时失去它们的意义。 |
| 5. | Characters enclosed in a bracket expression match only a single character for the position in the regular expression
括在中括号表达式中的字符只匹配处于正则表达式中该位置的单个字符。 |
| 6. | A typical use of a bracket expression is to specify matches of any upper - or lowercase alphabetic characters or any digits
中括号表达式的典型用途是指定任何大写或小写字母或任何数字的匹配。 |
| 7. | Matches the position at the beginning of an input string except when used in a bracket expression where it negates the character set
匹配输入字符串开始处的位置，但在中括号表达式中使用的情况除外，在那种情况下它对字符集求反。 |
