Question

Hello i am trying to modify any string to a valid variable made with Uppercase Underscore.

So for example if i have the following:

configGlossary:poweredByIcon -> CONFIG_GLOSSARY_POWERED_BY_ICON

124$32SomeSampleString_thatI_have -> SOME_SAMPLE_STRING_THAT_I_HAVE

myJSP -> MY_JSP but my regex produces MY_J_S_P

First i am using a function to create the Uppercase underscore from camelCase string.

so far i have been able to achieve the required result for everything except the last result example and also the case when there are numbers at start of the string. i have with the following regex. This will remove also the multiple underscores if any.

 String regex = "s/^[^a-zA-Z_]+|[^a-zA-Z_0-9]";
 String result = variableName.replaceAll(regex, "_").replaceAll("\\_+", "_");

so my question is how do produce the required result. is there a regex that will make me a valid variable from any string?

And is there a way to solve the last sample?

Answer 1

This will work for your provided samples:

public static String toVar(String str){
    str = str.replaceAll("^[^a-zA-Z_]+", "");
    str = str.replaceAll("[^a-zA-Z_0-9]+", "_");
    str = str.replaceAll("(?<=[a-z])(?=[A-Z])", "_");
    return str.toUpperCase();
}

Sample:

String s;
s = "myJSON";
System.out.println(s + " -> " + toVar(s));

s = "configGlossary:poweredByIcon";
System.out.println(s + " -> " + toVar(s));

s = "124$32SomeSampleString_thatI_have";
System.out.println(s + " -> " + toVar(s));

Output:

myJSON -> MY_JSON
configGlossary:poweredByIcon -> CONFIG_GLOSSARY_POWERED_BY_ICON
124$32SomeSampleString_thatI_have -> SOME_SAMPLE_STRING_THAT_I_HAVE