Let’s use the example String ‘dorchester’, and you want to extract ‘chest’, which goes from index 3 to index 7.
Substring and Slice
The syntax for both of these is the same:
- substring(startIndex [, endIndex])
- slice(startIndex [, endIndex])
EndIndex is not inclusive, so you usually want to do endIndex + 1.
To extract “chest”, we would run s.substring(3, 8) or s.slice(3, 8).
The syntax for substr is:
- substr(startIndex [,count])
Instead of the endIndex, you specify how many characters after the start you want to include.
Because “chest” is 5 characters, we want to use 5.
So the proper syntax would be s.substr(3, 5).