CODEWITHSUNDEEP
javainputtokendelimiterstringtokenizer
Craig K.
Craig K.

Reputation: 13

countTokens() always returns 1 with user input

Before we begin, I don't believe this is a repeat question. I've read the question entitled StringTokenzer countTokens() returns 1 with any string, but that does not address the fact that a properly delimited string is counted correctly, but a properly delimited input is not.

When using the StringTokenizer class I've found that the countTokens method returns different outcomes depending on the whether the argument in countTokens was a defined String or a user defined String. For example, the following code prints the value 4.

String phrase = "Alpha bRaVo Charlie delta";

StringTokenizer token = new StringTokenizer(phrase);
//There's no need to specify the delimiter in the parameters, but I've tried
//both code examples with " " as the delimiter with identical results

int count = token.countTokens();

System.out.println(count);

But this code will print the value 1 when the user enters:Alpha bRaVo Charlie delta

Scanner in = new Scanner(System.in);

String phrase;

System.out.print("Enter a phrase: ");

phrase = in.next();

StringTokenizer token = new StringTokenizer(phrase);

int count = token.countTokens();

System.out.println(count);

Upvotes: 1

Views: 144

Answers (4)

κροκς
κροκς

Reputation: 590

If you check the value of phrase, after invoking in.next(), you will see that's equal to "Alpha". By definition, Scanner's next() reads the next token.

Use in.nextLine() instead.

Upvotes: 0

zoku
zoku

Reputation: 7236

You could try using an InputStreamReader, instead of the Scanner:

BufferedReader in = new BufferedReader(new InputStreamReader(System.in));

String phrase = "";

System.out.print("Enter a phrase: ");

try {
    phrase = in.readLine();
} catch (IOException e) {
    e.printStackTrace();
}

StringTokenizer token = new StringTokenizer(phrase);

int count = token.countTokens();

System.out.println(count);

nextLine() of Scanner also got the job done for me, though.

If you want the delimiter to be a space-character specifically, you might want to pass it to the constructor of StringTokenizer. It will use " \t\n\r\f" otherwise (which includes the space-character, but might not work as expected if e.g. the \n-character is also present inside the phrase).

Upvotes: 0

pooja sharma
pooja sharma

Reputation: 39

Scanner in = new Scanner(System.in);

String phrase;

System.out.print("Enter a phrase: ");

phrase = in.nextLine();

System.out.print(phrase);

StringTokenizer token = new StringTokenizer(phrase);

int count = token.countTokens();

System.out.println(count);

Print phrase and check that in.next() is returning "Alpha".

As suggested above, Use in.nextLine().

Upvotes: 0

beatrice
beatrice

Reputation: 4431

Use in.nextLine() instead of in.next();

Upvotes: 3

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