Thread: Sets

Hi Ladies and Gents,

I'm trying to teach myself about sets from scratch and the uses of them and I have thought of a method that could be useful.

If I had a method called for example displayWordsInString() which takes a string argument called text.

Could I get this method to return a set consisting of words that are in the string referenced by the argument.

So myClass.displayWordsInString(" the train is late again ");


should print out an array:



[late,train,is,again,the]


the order of print out is not really that important to me!!


If there is a solution to this I could try out, it would really stretch my knowledge a bit , thanks again in advance to this great learning forum!!.

Look at the String class's split method. It will help you extract the words from the string.

String [] text =  ["late" ,"train", "is", "again", "the"];
 
text.split(",");
 
for ( int i = 0; i < text.length; i++)
 
{
  System.out.println(text[i]);
}

I get the following error
Semantic error: line 1. Message split( java.lang.String ) not understood by class'[Ljava.lang.String;'

Can you put me out my misery Norm and correct my code.... thanks a million.

Semantic error: line 1. Message split( java.lang.String ) not understood by class'[Ljava.lang.String;'

Read the API doc for the split() method. What does it take for an argument?
What argument did you give it in the code you posted?

[Ljava.lang.String
That is how the compiler refers to a String array.

split(String regex, int limit)

These are the arguments in the API but to be honest I dont know what they mean or how to implement them.

rGds

Originally Posted by av8

split(String regex, int limit)

These are the arguments in the API but to be honest I dont know what they mean or how to implement them.

The 'limit' argument is optional (there is an overloaded method that takes just a regex String). The API docs try to tell you what you need to know to use the method. If you don't know what a 'regex' or 'regular expression' is, follow the link.

I have tried String [] text = {"late" ,"train", "is", "again", "the"}; with the curlys instead of []

text.split(",");

and still get an error do i need to use import java.util.*;

I tried to explain your problem in post #6. Did you have any questions about what I said there.
Did you try the code I posted?

Yes thankyou Norm it worked A OK.