Java regex for replaceAll

Question

What is the regex expression for replace all the A char with A1, B->B1, C->C1, D->D1 and E->E1 string?

//AND(A<>B,C>D)?GREEN(E-E)
String expr ="AND(A<>B,C>D)?GREEN(E-E)";
String regex="";
expr.replaceAll(regex, "N1");
System.out.println(expr);

The result may be:

AND(A1<>B1,C1>D1)?GREEN(E1-E1)

Thank you

• michele: Now it's ok thanks
• Salem: _ has no special meaning in regex, maybe you are confusing it with SQL's replace syntax?
• azro: @1blustone maybe he wrote anything because he says he does not what to write ^^
• Federico Piazza: @michele, after your edit the question is clear, have just provided an answer

Answer 1

You can use a regex like this:

\b([A-E])\b

With the replacement string 11ドル

Bear in mind that in java you have to escape backslasher, so you have to use:

String expr = "AND(A<>B,C>D)?GREEN(E-E)";
expr = expr.replaceAll("\\b([A-E])\\b", "11ドル");
System.out.println(expr);

Java demo

Regex demo

enter image description here

Update: following your comment, if you want to extend the regex to all letters, then replace [A-E] to [A-Z].

• michele: it s not working with this expression AND(J<>Q,N-(N*10/100)>O) ...why?
• Federico Piazza: @michele because you said A, B, C, D and E. If you want to replace all letters, then change A-E to A-Z