onsider the regular expression a (([ab]a*) ∪ (c(bb)*))* .Which of the following are valid strings, as defined by the regular expression? (Choose as many as apply) Question 21 options: 巴克布 阿布克布 阿巴阿克 abcbbbbbba
时间: 2023-06-08 07:07:31 浏览: 39
根据给出的正则表达式 a (([ab]a*) ∪ (c(bb)*))*,可以分解得到以下内容:
- a 表示必须首先出现一个字母 a;
- (([ab]a*) ∪ (c(bb)*))* 表示后面可以跟随任意多次括号内部分组的内容,括号内部分组是由两部分通过并集(∪)组成,即 [ab]a* 和 c(bb)*,其中 [ab]a* 表示一个 a 后面可以跟随任意个 a 或者 b,c(bb)* 表示一个 c 后面必须跟随两个 b,后面还可以跟随任意多个 bb。
- 最终得到的是一个字符集,包括 a, ab, acbb, acbbbbbb, aba, abaa, acab, acabb, acabbbbbb。
因此,只有巴克布和阿巴阿克是符合给出的正则表达式的,选择 D:巴克布和阿巴阿克。
相关问题
Use a regular expression literal instead of the 'RegExp' constructor
Sure, using a regular expression literal is generally preferred over using the `RegExp` constructor. Here is an example:
Instead of using:
```
let regex = new RegExp('hello', 'i');
```
You can use a regular expression literal like this:
```
let regex = /hello/i;
```
It's shorter and easier to read.
Rename this field "SvcCd" to match the regular expression '^[a-z][a-zA-Z0-9]*$'.
Sure, I can help you with that! To rename the "SvcCd" field to match the regular expression '^[a-z][a-zA-Z0-9]*$', you can follow these steps:
1. Identify where the field "SvcCd" is located. Is it in a database table, a CSV file, a JSON file, or somewhere else?
2. Use the appropriate tool or programming language to rename the field. For example, if the field is in a SQL Server database table, you can use the ALTER TABLE statement to rename the column:
```
ALTER TABLE table_name
RENAME COLUMN SvcCd TO new_column_name;
```
If the field is in a CSV file, you can use a CSV editor or a programming language like Python to rename the column:
```
import pandas as pd
df = pd.read_csv('file.csv')
df = df.rename(columns={'SvcCd': 'new_column_name'})
df.to_csv('file.csv', index=False)
```
3. Make sure the new column name matches the regular expression '^[a-z][a-zA-Z0-9]*$'. This regular expression requires the first character to be a lowercase letter, followed by any combination of lowercase and uppercase letters and digits.
If the new column name does not match the regular expression, you may need to make additional modifications to the name until it does.
I hope this helps! Let me know if you have any further questions.
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