A regular expression is a sequence of characters which define a search pattern. Go language support regular expressions. A regular expression is used for parsing, filtering, validating, and extracting meaningful information from large text, like logs, the output generated from other programs, etc.
In Go regexp, you are allowed to find the leftmost index value of the specified regular expression in the given string with the help of the FindStringIndex() method. This method returns a two-element slice of integers which defines the location of the leftmost match in the given string of the regular expression and the match like str[loc:loc]. Or it will return nil if no match found. This method is defined under the regexp package, so for accessing this method you need to import the regexp package in your program.
func (re *Regexp) FindStringIndex(str string) (loc int)
[1 3] [8 10]  
Found: 345 with index value: [9 12]
- Golang | Finding Index of the Regular Expression present in Slice
- Golang | Extracting all the Regular Expression from the String
- Golang | Checking the string for the specified regular expression
- Golang | Extracting a Regular Expression from the String
- Golang | Replacing all String which Matches with Regular Expression
- Golang | Extracting Regular Expression from the Slice
- Golang | Checking the byte of slice for specified regular expression
- Finding the index value of specified byte in slice of bytes in Golang
- Check if the given characters is present in Golang String
- How to find the last index value of specified string in Golang?
- How to find the index value of specified string in Golang?
- Golang | How to find the index of rune in the string?
- Golang | Splitting a Slice Separated by the Specified Expression
- Check if the specified element is present in the slice of bytes in Golang
- How to count specific characters present in the slice in Golang?
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to email@example.com. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.