TCS selenium webdriver interview questions 2nd Dec

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  Introduce yourself  tell something about your last project?

  Count no. Of words and sentence in notepad and arrange them in ascending order?

  Write the format of XML file for BATCH EXICUTION?

  Please explain your project architecture with framework with diagram?

  What  are  the technical challanges you have faced?

. there are one string say Aattribute , so write a code to find the repeated word in that string 

  and it should work for case insensitive(work for lower case and upper case) ?

  Write a query for self join?

  how to take screenshot write code?

. if you have opened any web application and it is broken means it has changed its layout and other         thing which type of testing you will perform to check this?

   What are the things u stored in PageFactory ? Why ?

  Explain TestNG?

  What are the annotations U have Used and why ?

  Explain Agile Method?

  What is StringBuffer and StringBuilder?

  Difference between delete and truncate ?

Collections Set in Java

Collections:

• Collections in java is a framework that provides an architecture to store and display the data.
• Collections API provides interfaces and classes.
• Using Collection we can perform operations like searching,sorting,insertion,deletion,manipulation.
• Collections is nothing but group of different type of objects together as a single entity is also known as Collections.
• Collections are growable Nature.

• Collection Framework having Interfaces like Set,List,Map.Every Interface having classes.

Why Collection Came?

• Arrays are fixed in size.we can't increase size of Arrays.that's y only collections came.collections having growable nature.we can increase size.

Set Interface:

• A set is a collection that having only unique elements.Duplicate won't be there.
• Set having no index.
• Set allows only one null value.
• Set having classes like :

• HashSet
• LinkedHashMap
• TreeSet

HashSet:

HashSet having only unique elements.

HashSet having no Order.

HashSet allows only one null value.

Program for HashSet:

package.com.instanceofjava;

import.java.util.HashSet;

public class A{

public static void main(String args[]){

HashSet hashset=new HashSet();

hashset.add("Indhu");

hashset.add("Indhu");

hashset.add("Sindhu");

hashset.add("swathi");

hashset.add(null);

hashset.add(null);

hashset.add("Lavs");

Iterator it=hashset.iterator();

while(it.hasNext()){

System.out.println(it.next);

}

}

}

Output:

Indhu

null

Lavs

Sindhu

swathi

LinkedHashMap:

• LinkedHashMap allows only unique elements.
• LinkedHasMap allows Insertion order.
• LinkedHashMap allows only one null value.

Program for LinkedHashSet;

package.com.instanceofjava;

import.java.util.LinkedHashSet;

public class testSet{

public static void main(String args[]){

LinkedHasMap linkedHashMap=new LinkedHasMap();

linkedHashMap.add("Indhu');

linkedHashMap.add("Indhu");

linkedHashMap.add("Sindhu");

linkedHashMap.add("Bindhu");

linkedHashMap.add(null);

linkedHashMap.add(null);

Iterator it=linkedHashMap.iterator();

while(it.hasNext()){

System.out.println(it.next);

}

}

}

Output:

Indhu

Sindhu

Bindhu

null

TreeSet:

• TreeSet Allows only Unique elements.
• Treeset having sorted order
• TreeSet doesn't allow  any null value.

Program for TreeSet:

package.com.instanceofjava;

import.java.util.TreeSet;

Public class testSet2{

public static void main(String args[]){

TreeSet treeSet=new treeSet();

treeSet.add("Sindhu");

treeSet.add("Sindhu");

treeSet.add("Indhu");

treeSet.add("Bindhu');

Iterator it=treeSet.iterator();

while(it.hasNext()){

System.out.println(it.next);

}

}

}

Output:

Bindhu

Indhu

Sindhu

• in Set interface if you want to add elements you can use add() method.
• If you want to remove you can use remove() method.

String vs stringbuffer vs stringbuilder

1.Definition:

• String is an immutable sequence of characters.
• StringBuffer is mutable sequence of characters.
• StringBuilder is also mutable sequence of characters.

The only difference between StringBuffer and StringBuilder: 

• StringBuffer object is thread safe , it means StringBuffer object is modified by multiple concurrently, because  all its methods are declared as "synchronized".
• StringBuilder class is given in jdk 1.5 version as non thread -safe class, means all its methods are non synchronized methods.
• So , in single model application we must use StringBuilder, so that object locking and unlocking will not be there, hence performance is increased.
• In single thread model application operations are executed in sequence hence there is no chance of object corruption.

When should we choose String and StringBuffer? 

• If we do not want to store string modifications in the same memory we must choose String.
• To do modifications in the same memory, we must choose StringBuffer or StringBuilder.

 Advantage and disadvantage in String: 

• Advantage : Since modifications are preserving in another memory location, we will have both original and modified values.
• Disadvantage: It consumes lot memory for every operation, as it stores it modifications in new memory. So it leads to performance issue.
• Solution: To solve this performance issue , in projects developers store string data using StringBuilder or StringBuffer after all modifications they convert into String and pass it back to user.

Advantage and disadvantage of StringBuffer or StringBuilder:

• Advantage: It given high performance because consumes less memory as all modifications stored in same memory.
• Disadvantage: Original value will not be preserved.

2.Creating String , StringBuffer objects: 

String:

• String object can be created in two ways.
• By using string literal : String str="instance of java ";
• By using its constructors: String str= new String("instaneofjavaforus") ;

StringBuffer:

• By using its available constructors
• StringBuffer str= new StringBuffer();

StringBuilder:

• By using its available constructors
• StringBuilder str= new StringBuilder ();

3.Special operations those we can only perform on StringBuffer and StringBuilder: 

1. append
2. insert
3. delete
4. reverse

•  Since string is immutable we cannot perform these operations on String.

4.Concatenation:

• Using String object we can concat new string to the current  string in two ways.

1. Using + operator
2. using concat() method.

• Using StringBuffer we can perform concat operation only in one way

1. Using append() method

• Using StringBuilder we can perform concat operation only in one way

1. Using append() method

package com.javaforus;

public Class SBDemo{ 

public static void main (String args[]) {

        String str="Java";

        StringBuffer sb= new StringBuffer("Java");

        StringBuilder sbr= new StringBuilder("Java");

       System.out.println(str.concat(" language"));    

       System.out.println(sb.append(" language"));

        System.out.println(sbr.append(" language"));

}

}

OutPut:

Java language

Java language

Java language

5.Comparison:

• Using equals() method String objects are compared with state, because it is overridden in this class. Also hashcode(0 method is overridden in order to satisfy equals() method contract.

• But in StringBuffer and in StringBuilder equals() method is not overridden , so using equals() method their object are compared with reference.