Regular expression introduction. 1. if a regular expression has never been used before, it may be unfamiliar with this term and concept. However, they are not as novel as you think. Recall 1. Regular expression
If you have never used a regular expression, you may not be familiar with this term or concept. However, they are not as novel as you think.
Remember how to find files on the hard disk. Are you sure you want to use? And * characters to help find the file you are looking .? In the character matching file name
A single character, while * matches one or more characters. A file such as 'data ?. The following files can be found in the dat mode:
Data1.dat
Data2.dat
Datax. dat
DataN. dat
If "*" is used instead? Characters to expand the number of files found. 'Data *. dat 'can match all the following file names:
Data. dat
Data1.dat
Data2.dat
Data12.dat
Datax. dat
DataXYZ. dat
Although this file search method is certainly very useful, it is also very limited .? And * the limited capabilities of wildcards allow you to have an overview of what a regular expression can do.
But regular expressions are more powerful and flexible.
If the regular expression is not used before, the term and concept may be unfamiliar. However, they are not as novel as you think. Think back...
