Create a String from other String in Java-CodePudding

Given a String like this: String secret = “H)86(e,@€l:-;l?,;5o” they ask me to make a new String with only the letters (and spaces if they are) to reveal a secret message….

I tried with a for loop and the charAt method, but it didn’t work… ideas? I would appreciate plain explanation as I’m noob on programming. Thanks!!

CodePudding user response：

Use a „regular expression“ (RegEx) and https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#replaceAll-java.lang.String-java.lang.String- to strip out all unwanted characters.

Something like this will do:

var hello = "H)86(e,@€l:-;l?,;5o".replaceAll("[^a-zA-Z\\s]","");

CodePudding user response：

Have you tried a regular expression that matches only letters and space?

like this: "[a-zA-Z ]*"

CodePudding user response：

You can do that by a regular expression (regex) in String#replaceAll(regexString, replaceString).

String decrypted = secret.replaceAll("[^A-Za-z ]", "");

This will find everything, except A to Z, a to z, space and will replace it by "" (nothing).

You can test such expressions here: https://regex101.com/