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selenium-Java-interview

Important Java Selenium Questions/Codes for Software Test Automation Learners, Part3

This page contains Java code for below questions:

1. Reverse characters

2. Create Palindrome

3. Find unique characters(Remove duplicate characters)

4. Count the repetition of characters(find duplicate characters) in a given string

5. Create Fibonacci sequence/number

6. Regular expression

Find the sum of all the numbers present in a given string containing alphanumeric and special characters. 

7. Sum all the characters present in your name

8. Find non-duplicate characters in a given string.

9. Check if the given number is a "prime number"

10. Odd numbers present in an array  

11. Find the second most repeated char in a given string 

12. Reformat the given string : "asdfsdafgde" => "2a-2s-3d-1e-2f-1g"


1. Reverse characters

     public static void reverseChar() {

           String str = "asdfghjkl";

           //lkjhgfdsa

           String expStr = "";

           int len = str.length();

           for(int i=len-1;i>=0;i--) {

                char ch = str.charAt(i);

                String strCh = Character.toString(ch);

                expStr = expStr+strCh;

           }

           System.out.println("The reverse string is : "+expStr);

     }

OUTPUT:
The reverse string is : lkjhgfdsa

2. Create Palindrome

     public static void palindrome() {

           String str = "level";

           //lkjhgfdsa

           String expStr = "";

           int len = str.length();

           for(int i=len-1;i>=0;i--) {

                char ch = str.charAt(i);

                String strCh = Character.toString(ch);

                expStr = expStr+strCh;

           }

           //System.out.println("The reverse string is : "+expStr);

          

           String strInSameOrder = "";

           for(int i=0;i<len;i++) {

                char ch = str.charAt(i);

                String strCh = Character.toString(ch);

                strInSameOrder = strInSameOrder+strCh;

           }

           //System.out.println("The string in right/same order is : "+strInSameOrder);

          

           if(expStr.equals(strInSameOrder)) {

                System.out.println("The given string is a Palindrome.");

           } else {

                System.out.println("The given string is NOT a Palindrome.");

           }

     }

OUTPUT:

The given string is a Palindrome.


3. Find unique characters(Remove duplicate characters)

     public static void uniqueChar() {

          

           String str = "asdfsgdfsdasderfvdera";

          

           ArrayList<String> alist = new ArrayList<>();

           char ch = str.charAt(0);

           String strCh = Character.toString(ch);

           alist.add(strCh);

           int len = str.length();

          

           for(int i=0;i<len;i++) {

                char chh = str.charAt(i);

                String strChh = Character.toString(chh);

                if(!alist.contains(strChh)) {

                      alist.add(strChh);

                }

           }

           System.out.println("The unique characters are : "+alist);

 

     }

OUTPUT:

The unique characters are : [a, s, d, f, g, e, r, v]


4. Count the repetition of characters(find duplicate characters) in a given string

     public static void duplicateChar() {

           String str = "asdfsgdfsdasderfvdera";

           int len = str.length();

          

           HashMap<String, Integer> map = new HashMap<>();

           for(int i=0;i<len;i++) {

                char ch = str.charAt(i);

                String strCh = Character.toString(ch);

                if(map.containsKey(strCh)) {

                      map.put(strCh, map.get(strCh)+1);

                } else {

                      map.put(strCh, 1);

                }

           }

           System.out.println("The duplicate chars are : "+map);

          

     }

 

OUTPUT:

The duplicate chars are : {a=3, r=2, s=4, d=5, e=2, f=3, v=1, g=1}


5. Create Fibonacci sequence/number

     public static void fibonacciSeq() {

           // 0,1,1,2,3,5,8,13,....

           ArrayList<Integer> alist = new ArrayList<>();

           alist.add(0);

           alist.add(1);

           for(int i=2;i<10;i++) {

                alist.add(alist.get(i-1)+alist.get(i-2));

           }

           System.out.println("The Fibonacci sequence is :"+alist);

     }

OUTPUT:

The Fibonacci sequence is :[0, 1, 1, 2, 3, 5, 8, 13, 21, 34]


6. Regular expression

Find the sum of all the numbers present in a given string containing alphanumeric and special characters. 

     public static void reqExpressionSum() {

           String str = "as3df5cs@11we4zas#21$juyt";

           String strArr = str.replaceAll("[^0-9]", " ");

           System.out.println("strArr = "+strArr);

           String[] strSum = strArr.split(" ");

           System.out.println("Array of numbers = "+Arrays.toString(strSum));

          

           int len = strSum.length;

           int sum = 0;

           for(int i=0;i<len;i++) {

                if(!strSum[i].equals("")) {

                      int x = Integer.parseInt(strSum[i]);

                      sum = sum+x;

                }

           }

           System.out.println("Sum of the numbers present in the string = "+sum);

     }

    

OUTPUT:

strArr =   3  5   11  4    21    

Array of numbers = [, , 3, , 5, , , 11, , 4, , , , 21]

Sum of the numbers present in the string = 44



7. Sum all the characters present in your name

     public static void sumName() {

           String name = "John Smith";

           int nameSum = 0;

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

                char nthchar = name.charAt(i);

                //System.out.println("nthchar = "+nthchar);

                int j = nthchar;

                System.out.println("nthchar, j = "+nthchar+" "+j);

                nameSum = nameSum+nthchar;

           }

           System.out.println("Summation of all characters in the name = "+nameSum);

     }

 

OUTPUT:

nthchar, j = J 74

nthchar, j = o 111

nthchar, j = h 104

nthchar, j = n 110

nthchar, j =   32

nthchar, j = S 83

nthchar, j = m 109

nthchar, j = i 105

nthchar, j = t 116

nthchar, j = h 104

Summation of all characters in the name = 948



8. Find the non duplicate chars in a given string

     public static void nonDuplicateChar() {

           String str = "asdfsgdfsdasdferfvdera";

           int len = str.length();

           HashMap<String,Integer> map = new HashMap<>();

           //String chStr = "";

           for(int i=0;i<len;i++) {

                String str1= Character.toString(str.charAt(i));

                if(map.containsKey(str1)) {

                      map.put(str1, map.get(str1)+1);

                } else {

                      map.put(str1, 1);

                }

           }

           System.out.println("The char repeation is like this "+map);

          

           ArrayList<Integer> alist = new ArrayList<>(map.values());

           ArrayList<String> blist = new ArrayList<>(map.keySet());

           for(int i=0;i<alist.size();i++) {

                if(alist.get(i)==1) {

                      System.out.println("The unique numebr ="+alist.get(i)+blist.get(i)); //OR user concat like below

                      //System.out.println("The unique numebr ="+Integer.toString(alist.get(i)).concat(blist.get(i)));

                }

           }

          

     }

Output:

The char repeation is like this {a=3, r=2, s=4, d=5, e=2, f=4, v=1, g=1}

The unique numebr =1v

The unique numebr =1g

 

9. Find if the given number is a Prime number such as 2,3,5,7,11,13,17

     public static void primenum() {

           int x = 9;

           boolean isPrimeNumber = true;

          

           if(x<=1) {

                isPrimeNumber=false;

           }

           for(int i=2;i<x;i++) {

            if((x % i == 0)) {

                isPrimeNumber = false ;

                break ;

            }

           }

           System.out.println("is the given number prime ? "+isPrimeNumber);

     }

Output:

When x=2:

is the given number prime ? true

when x=9;

is the given number prime ? false

 

 10. odd numbers present in an array

     public static void oddNum() {

           int[] num = {1,2,4,5,7,6,8,3,0,10,11,15,16};

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

                if(!(num[i]%2==0)) {

      System.out.println("Number at index "+i+" is an odd number "+num[i]);

                }

           }

     }

Output:

Number at index 0 is an odd number 1

Number at index 3 is an odd number 5

Number at index 4 is an odd number 7

Number at index 7 is an odd number 3

Number at index 10 is an odd number 11

Number at index 11 is an odd number 15

 

11. find the second most repeated char in a given string

     public void secMostRepChar() {

           String str = "asdfsgdfsdasdferfvdera";

           int len = str.length();

          

           HashMap<String, Integer> map = new HashMap<>();

           for(int i=0;i<len;i++) {

                char ch = str.charAt(i);

                String strCh = Character.toString(ch);

                if(map.containsKey(strCh)) {

                      map.put(strCh, map.get(strCh)+1);

                } else {

                      map.put(strCh, 1);

                }

           }

           System.out.println("The duplicate chars are : "+map);

          

           int mapLen = map.size();

           int map2ndVal = 0;

           ArrayList<Integer> alist = new ArrayList<>(map.values());

           ArrayList<String> blist = new ArrayList<>(map.keySet());

           for(int i=1;i<mapLen;i++) {

                if((alist.get(i-1))>map2ndVal && (alist.get(i-1)<alist.get(i))) {

                      map2ndVal=alist.get(i-1);

                }

           }

           System.out.println("The second highest repeated number : "+map2ndVal);

           ArrayList<String> clist = new ArrayList<>();

           for(int i=0;i<alist.size(); i++) {

                if(alist.get(i)==map2ndVal) {

             //clist.add(blist.get(i)+Integer.toString(map2ndVal)); OR                      clist.add((blist.get(i)).concat(Integer.toString(map2ndVal)));

                }

           }

           System.out.println("The second highest repeated char/s : "+clist);

     }

Output:

The duplicate chars are : {a=3, r=2, s=4, d=5, e=2, f=4, v=1, g=1}

The second highest repeated number : 4

The second highest repeated char/s : [s4, f4]

 

12. Reformat the given string

public static void reformatString() {

           String str = "asdfsdafgde"; //2a-2s-3d-1e-2f-1g

           int len = str.length();

           HashMap<String,Integer> map = new HashMap<>();

           for(int i=0;i<len;i++) {

                String str1= Character.toString(str.charAt(i));

                if(map.containsKey(str1)) {

                      map.put(str1, map.get(str1)+1);

                } else {

                      map.put(str1, 1);

                }

           }

           System.out.println("The char repeation is like this "+map);

           ArrayList<String> alist = new ArrayList<>(map.keySet());

           ArrayList<Integer> blist = new ArrayList<>(map.values());

           ArrayList<String> clist = new ArrayList<>();

           String strNewFormat = "";

           for(int i=0;i<map.size();i++) {

                String str1 = Integer.toString(blist.get(i))+alist.get(i);

                clist.add(str1);

 

           }

           System.out.println("combined elements "+clist);

           for(int i=0;i<map.size()-1;i++) {

                //strNewFormat=strNewFormat+clist.get(i)+"-"; //OR

                strNewFormat = strNewFormat.concat(clist.get(i)).concat("-");

           }

           strNewFormat=strNewFormat+clist.get(map.size()-1);

           System.out.println("New formated string: "+strNewFormat);

     }

Output:

The char repeation is like this {a=2, s=2, d=3, e=1, f=2, g=1}

combined elements [2a, 2s, 3d, 1e, 2f, 1g]

New formated string: 2a-2s-3d-1e-2f-1g