How to count vowels in a String?

Here you will be asked to enter a String of your own choice and then you will get the number of vowels from that String.

In the program code given below, you will be asked to enter the String first as can be observed from the method of java.io.*; package which is BufferedReader();. The compiler will read the String once you enter it through readLine(); method. Then we have taken a variable- count = 0. Now, we have applied a loop here which will go up to the String's length and will find the number of vowels one by one as shown in the output.

Program:

import java.lang.String;
import java.io.*;
import java.util.*;

public class CountVowels{

public static void main(String args[])throws IOException{
  BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
  System.out.println("Enter the String:");
  String text = bf.readLine();
  int count = 0;
  for (int i = 0; i < text.length(); i++) {
  char c = text.charAt(i);
  if (c=='a' || c=='e' || c=='i' || c=='o' || c=='u') {
  count++;
  }
  }
  System.out.println("There are" + " " + count + " " + "vowels");
}
}

Output:

Enter the String:
This is a new world
There are 5 vowels

Java Compare String (== operator)

This section describes how two string references are compared?

     If two String variables point to the same object then these two variables are called references for the same object.So to check this comparison programmatically,  == operator is used. If two variables refers the same object then thisoperator returns true value and if they don't then false value is returned. The essential point to remember while comparing strings with this operator is that it compares the references the two strings are pointing to rather than comparing the content of the string.  The following program uses this operator compare the two strings. If both strings are equal, it will display a message "The given strings are equal" otherwise it will show "The given string are not equal".

Description:

This is the method that compares an object values and returns Boolean type value either 'true' or 'false'. If it returns 'true' for the both objects, it will be equal otherwise not. Here in this case you will see that both the strings come out to be same that is because they have been allocated to the same memory.

Let us see an Example:

public class stringmethod{
  public static void main(String[] args){
  String string1 = "Hi";
  String string2 = new String("Hello");
  if (string1 == string2) {
  System.out.println("The strings are equal.");
  } else {
  System.out.println("The strings are unequal.");
  }
  }
}

Output

The strings are unequal.