java program to print vowels in a string

1 
2package org.arpit.java2blog;
3 
4import java.util.HashSet;
5import java.util.Scanner;
6import java.util.Set;
7 
8public class VowelFinder
9{
10    public static void main(String args[])
11    {
12        Scanner scanner = new Scanner(System.in);
13 
14        System.out.print("Enter an String : ");
15        String str = scanner.next();
16 
17        Set<Character> set=new HashSet<Character>();
18        for (int i = 0; i < str.length(); i++) {
19            char c=str.charAt(i);
20            if(isVowel(c))
21            {
22                set.add(c);
23            }
24        }
25 
26        System.out.println("Vowels are:");
27        for (Character c:set) {
28            System.out.print(" "+c);
29        }
30 
31        scanner.close();
32    }
33 
34    public static boolean isVowel(char character)
35    {
36 
37        if(character=='a' || character=='A' || character=='e' || character=='E' ||
38                character=='i' || character=='I' || character=='o' || character=='O' ||
39                character=='u' || character=='U'){
40            return true;
41        }else{
42            return false;
43        }
44    }
45 
46}
47 
48

1String str = "hello";
2String vowels = "aeiou";
3
4for(char c : str) if(vowels.contains(c)) System.out.println(c + "");

1import java.util.Scanner;
2import java.util.*;
3
4class Test{
5    
6    public static boolean isVowel(char ch){
7        if(ch == 'A' || ch == 'a' || ch == 'E' || ch == 'e' || ch == 'i' || ch == 'I' || ch == 'o' || ch == 'O' || ch == 'u' || ch == 'U'){
8            return true;
9        }
10        return false;
11    }
12    
13    public static void main(String args[]){
14        
15        Scanner scan = new Scanner(System.in);
16        List<String> arr = new ArrayList<String>();
17        String str = scan.nextLine();
18        String words[] = str.split("\\s");
19        
20        for(String k: words){
21            boolean flag = false;
22            boolean f1 = true;
23            boolean f2 = true;
24            if(k.length()<=2){
25                continue;
26            }
27            for(int i = 0 ; i < k.length() ; i = i + 2){
28                if(isVowel(k.charAt(i))==false){
29                    f1 = false;
30                    break;
31                }
32            }
33            for(int i = 1 ; i < k.length() ; i = i + 2){
34                if(isVowel(k.charAt(i))==false){
35                    f2 = false;
36                    break;
37                }
38            }
39            if(f1 == true || f2 == true){
40                flag = true;
41            }
42            if(flag == true){
43                arr.add(k);
44            }
45        }
46        if(arr.size()==0){
47            System.out.print(-1);
48        }
49        else{
50            for(int i = 0 ; i < arr.size() ; i++)
51            {
52                System.out.print(arr.get(i) + " ");
53            }
54        }
55        scan.close();
56    }
57    
58}