Java String Exercise

I am working on an exercise in JAVA 1.8 that goes like this.
I have a String : "Able was I, ere I saw Elba."
I need to remove spaces and punctuation and capitalize it all.
Then I need to save a copy of it in reverse order and compare the two to see if they are the same.

Does anyone have a suggestion on how they might achieve this ?
I was thinking along the lines of a regex /[a-zA-Z]+/g as a possibility. But I don't know how to extract the words using a RegEx.
The result of the extraction would have the above expression returned as "ABLEWASIEREISAWELBA" .

Thanks,

Dave

David King

Asked: 2016-07-26

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1 Solution

LVL 86

CEHJCommented: 2016-07-26

Some pointers:

String.toUpperCase
String.replace
StringBuilder.reverse

David KingDirector I.T. SystemsAuthor Commented: 2016-07-26

Thanks, I'll research the API docs on those.

David KingDirector I.T. SystemsAuthor Commented: 2016-07-26

I have tested my RegEx /[a-zA-Z]+/g on my test string and it selects all of the words correctly. Is there a String class method that I can use that will allow me to use my RegEx expression to select the Words in my String and Return them back as a string, leaving the un-selected text behind?
?

LVL 86

CEHJCommented: 2016-07-26

I have tested my RegEx /[a-zA-Z]+/g on my test string and it selects all of the words correctly.

How and where?

Is there a String class method that I can use that will allow me to use my RegEx expression to select the Words in my String and Return them back as a string

That's not really how regex works. You need to think about replacement

David KingDirector I.T. SystemsAuthor Commented: 2016-07-26

I am trying to use the String.replace(regex , string) method to get the job done.

Like this;

public class PalCode
{

public PalCode()
{
String palString = new String("Able was I, ere I saw Elba."); // original input String
String workedString = new String(""); // String after manipulation
workedString = palString.replace("[^a-zA-Z]+/g" , "");
System.out.println("Manipulated string result is: " + workedString);

}
}// end class PalCode

The regex expression should match character that are NOT a-z or A-Z and replace them with "nothing".
The program runs and compiles without any errors but the regex has NO effect. ??

David KingDirector I.T. SystemsAuthor Commented: 2016-07-26

OK, I got it. This works.

public class PalCode
{

public PalCode()
{
String palString = new String("Able was I, ere I saw Elba."); // original input String
String workedString = new String(""); // String after manipulation
workedString = palString.replaceAll("[^a-zA-Z]+" , "").toUpperCase();
System.out.println("Manipulated string result is: " + workedString);

}
}// end class PalCode

("Able was I, ere I saw Elba."); // original input String
Manipulated string result is: ABLEWASIEREISAWELBA

LVL 32

awking00Commented: 2016-07-26

The String replace method will replace a char sequence or array. I think you should look at the replaceAll method which takes a regular expression as its first argument.