How do I count the number of words in a string?

Question

I need to count the number of words and I am assuming the correct way to do it is by calculating the number of times that the previous character in a string is not a letter

Answer 1

Use just like this

String s = "I am Juyel Rana, from Bangladesh";
int count = s.split(" ").length;

Answer 2

You can use String.split() to convert the string into an array, with one word in each element. The number of words is given by the length of the array:

int words = myString.split("\s+").length;

Answer 3

This problem is slightly more complicated than your algorithm allows.

• What if there are two or more spaces in a row?
• What if the string starts or ends with whitespace (or non-word characters)?

This looks like homework, so I don't want to provide any code. I suggest an alternative approach which is simpler to think about.

• Walk through the characters in the string, one by one.
• Do something to remember if you are currently scanning a word or if you are not currently scanning a word.
• Do something to determine when you enter or leave a word, and increment your counter accordingly.

Answer 4

The following program will count the number of words in a sentence. In this program, we are counting alphabets just after space. The alphabet can be of lower case or upper case. We are inserting a space at the beginning since people don't start a sentence with space. We also need to take care that any special character or number should not be counted as a word.

`import java.util.Scanner; public class WordSent {

public static void main(String[] args) {

    Scanner in= new Scanner(System.in);
    System.out.println("Enter the sentence");
    String str=in.nextLine();
    String space=" ";
    String spaceword=space.concat(str);

    int count=0;
    for(int i=0; i<spaceword.length()-1;i++)
    {
        for (int k=0; k<=25; k++)
        {
        if(spaceword.charAt(i)==' '&& (spaceword.charAt(i+1)==((char)(65+k)) || spaceword.charAt(i+1)==((char)(97+k))))
        {
            count++;
        }
      }
     }
    System.out.println("Total number of words in a sentence are" +" :  "+   count);
     }
    }`

Answer 5

Addressing the code directly, your first loop has i=0 as the first value of i, but then you ask for

string.charAt(i-1) = string.charAt(-1),

which is where your array-out-of-bounds is coming from.

The second loop has another problem:

for(int j = 0; i < alphabets.length(); j++) {

You may also want to consider apostrophes as parts of words as well.

Answer 6

The reason you are getting an IndexOutOfBoundsException is probably because when i is 0 your inner loop will have string.charAt(i-1) which will throw an exception since 0-1 is -1. If you fix that your method might work, although you can use more efficient techniques.