Regular expressions look for similar words--regular expressions

This paper is familiar with the application of regular expressions by showing the structure of different regular expressions and the techniques used in practical applications.

Problem Description:

In this example you have to solve the following problems.

1, want to find all the color and colour in a string.

2. To find any of these 3 words that end with "at": Bat, Cat, or rat.

3, want to find the end of phobia words.

4. The usual variants of the name "Steven" you want to find: Steve, Steven and Stephen.

5, want to match the term "regular expression" all the common forms.

Solution:

The following is a sequential list of regular expressions used to resolve these issues. In all of these solutions, the case-insensitive option is used.

question 1:color and colour

\bcolou?r\b

Regular options: case-insensitive

Regular genres:. NET, Java, JavaScript, PCRE, Perl, Python, Ruby

Question 2:bat, cat or rat

\b[bcr]at\b

Regular options: case-insensitive

Question 3: words ending with "phobia"

\b\w*phobia\b

Regular options: case-insensitive

Question 4: Steve, Steven and Stephen

\bste (?: ven?| Phen) \b

Question 5:variants of "regular expression"

\breg (?: Ular· expressions?| Ex (?:p s?| E[SN])? \b

Regular options: case-insensitive

Regular genres:. NET, Java, JavaScript, PCRE, Perl, Python, Ruby

Analytical:

\b #判断一个单词边界位置

Reg #匹配 "Reg"

(?: #分组但是不捕获

Ular\ # match "Ular"

Expressions? # match ' expression ' or ' expressions '

| Or

Ex # match "ex"

(?: # grouped but not captured

Ps? # match ' P ' or ' ps '

| Or

E[SN] # match "es" or "en"

)? # end non-capture grouping, entire grouping is optional

) # End of non-capture grouping

\b #判断一个单词边界位置

Note: all 5 regular expressions use a word boundary (<\b>) to ensure that only the whole word is matched.

The above is the entire content of this article, I hope to help you learn, but also hope that we support the cloud habitat community.