Basic Regex Expression Subsitution

Question

Is there a way to check if there is a regex match and then perform a substitution on part of the match?

Ex. -> "a3c" if "[1-9]c$" -> "a3" (if there is a "NUMc" at the end take off the "c")

specifically trying to generate a mapping a rules in to perform operations such as:

rule.put(String regex, String replacement) 
rule.put("[1-9]c$","");

to be able to call:

"a3c".replace(rule.key,rule.value) //delete just the "c" not the whole "3c".

Also I know that i can make an if statement to check if it matches and then call a replacement but i want to see if there is a neat one liner :)

Answer 1

Regex: (\\d+)c$ Substitution: $1

Details:

• () Capturing group
• \d Matches a digit (equal to [0-9])
• + Matches between one and unlimited times
• $ Asserts position at the end of the string
• $1 Group 1.

Java code:

String text = "a3c";
text = text.replaceAll("(\\d+)c$", "$1");
System.out.print(text); // a3

Code demo