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Q611. Write a Program to print count of each character in a String.

Ans. public class BuggyBread {
public static void main(String args[]) {
Map<Character, Integer> countMap = new HashMap();
String str = "hello world";
for (char character : str.toCharArray()) {
if (countMap.containsKey(character)) {
countMap.put(character, countMap.get(character) + 1);
} else {
countMap.put(character, 1);
}
}
System.out.println(countMap);
}
}

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Q612. Write a Program to only print characters that have occured more than once in a String

Ans. public class BuggyBread{
public static void main (String args[]) {
Set<Character> set = new HashSet();
Set<Character> setWithDuplicateChar = new HashSet();
String str = "hello world";
for(char character: str.toCharArray()){
if(set.contains(character)){
setWithDuplicateChar.add(character);
} else {
set.add(character);
}
}

System.out.println(setWithDuplicateChar);
}
}

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Q613. Write a Program to print all numbers till 100 that are divisible by 5

Ans. public class BuggyBread{
public static void main (String args[]) {
   for(int counter=1;counter<=100;counter++){
      if(counter % 5 == 0){
         System.out.println(counter);
      }
   }
}
}

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Q614. Write a Program to print 1 (1 time) , 2 ( 2 times ) and so on till 100.

Ans. public class BuggyBread1{
public static void main (String args[]) {
   for(int x=1;x<=100;x++){
      for(int y=1;y <= x;y++){
         System.out.println(x);
      }
   }
}
}

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Q615. Write a Program to print series like

1
12
123
1234
12345

till 100

Ans. public class BuggyBread{
public static void main (String args[]) {
   for(int x=1;x<=100;x++){
      for(int y=1;y <= x;y++){
         System.out.print(y);
      }
      System.out.println("
");
   }
}
}

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Q616. Write a program for 0 and cross games?

^{This question was recently asked at 'Compro Technologies'.This question is still unanswered. Can you please provide an answer.}

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Q617. Given a sorted array, write a program to check if two elements sum up to third.

^{This question was recently asked at 'Facebook'.This question is still unanswered. Can you please provide an answer.}

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Q618. Write a program to print two digit numbers that fulfil following criteria

Summing their digits and then multiplying with 3 should result in the number

For ex - 27 , (2+7) * 3 = 27

Ans. public class BuggyBread {
   public static void main(String args[]) {
      for(int x=10;x<100;x++){
         int tensDigit = x/10;
         int unitDigit = x%10;

         if((tensDigit+unitDigit)*3 == x){
            System.out.println(x);
         }
      }
   }
}

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Q619. Write Code showing Inheritance

Ans. class A {
public void test() {
System.out.println("Class A Test");
}
}

class B extends A {
public void test() {
System.out.println("Class B Test");
}
}

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Q620. Write a Program / Code showing Inheritance and overridding

Ans. class A {
public void test() {
System.out.println("Class A Test");
}
}

class B extends A {
public void test() {
System.out.println("Class B Test");
}

public static void main(String[] args){
A a = new B();
a.test(); // will print Class B Test
}
}

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Q621. Write a Program to find the longest word in a string

Ans. public class BuggyBread {
   public static void main(String args[]) {
      String str = "We are what we repeatedly do; excellence, then, is not an act but a habit.";
      String longestWord = "";

      str = str.replaceAll(",","");
      str = str.replaceAll(";","");
      str = str.replaceAll("/.","");

      for(String word: str.split(" ")){
         if(word.length() > longestWord.length()){
            longestWord = word;
         }
      }

      System.out.println(longestWord);
   }
}

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Q622. Write a Program that prints the repeated words in a String

For example -

We are what we repeatedly do; excellence, then, is not an act but a habit.

should print we, should count for case insensitive words too

Ans. public class BuggyBread {
   public static void main(String args[]) {
      Map<String,Integer> wordLength = new HashMap();

      String str = "We are what we repeatedly do; excellence, then, is not an act but a habit.";
      String longestWord = "";

      str = str.replaceAll(",","");
      str = str.replaceAll(";","");
      str = str.replaceAll("/.","");
      str = str.toLowerCase();

      for(String word: str.split(" ")){
         if(wordLength.containsKey(word)){
            wordLength.put(word, wordLength.get(word).intValue() + 1);
         } else {
            wordLength.put(word, 1);
         }
      }

      for(Map.Entry<String, Integer> entry:wordLength.entrySet()){
         if(entry.getValue().intValue() > 1){
            System.out.println(entry.getKey());
         }
      }
   }
}

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Q623. Write a Program that prints words longer than 5 characters in a String

For example

We are what we repeatedly do; excellence, then, is not an act but a habit

should print

repeatedly
excellence

Ans. public class BuggyBread1 {
   public static void main(String args[]) {
      Map<String,Integer> wordLength = new HashMap();

      String str = "We are what we repeatedly do; excellence, then, is not an act but a habit";
      String longestWord = "";

      str = str.replaceAll(",","");
      str = str.replaceAll(";","");
      str = str.toLowerCase();

      for(String word: str.split(" ")){
            wordLength.put(word, word.length());
      }

      for(Map.Entry<String, Integer> entry:wordLength.entrySet()){
         if(entry.getValue().intValue() > 5){
            System.out.println(entry.getKey());
         }
      }
   }
}

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Q624. Write a Program to print 3 smallest words in a String

Ans. public class BuggyBread {
   public static void main(String args[]) {
      Map<String,Integer> wordLength = new HashMap();

      String str = "We are what we repeatedly do; excellence, then, is not an act but a habit";

      str = str.replaceAll(",","");
      str = str.replaceAll(";","");
      str = str.toLowerCase();

      for(String word: str.split(" ")){
            wordLength.put(word, word.length());
      }

      List<Map.Entry<String, Integer>> list = new LinkedList<Map.Entry<String, Integer>>( wordLength.entrySet() );

      Collections.sort( list, new Comparator<Map.Entry<String, Integer>>()
{
public int compare( Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2 )
{
return (o1.getValue()).compareTo( o2.getValue() );
}
} );

      int countWords = 1;

      for(Map.Entry<String, Integer> entry:list){
         if(countWords <= 3){
            System.out.println(entry.getKey());
         }

         countWords++;

      }
   }
}

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Q625. Write a Program to print 3 largest words in a String

Ans. public class BuggyBread {
public static void main(String args[]) {
Map<String,Integer> wordLength = new HashMap();

String str = "We are what we repeatedly do; excellence, then, is not an act but a habit";

str = str.replaceAll(",","");
str = str.replaceAll(";","");
str = str.toLowerCase();

for(String word: str.split(" ")){
wordLength.put(word, word.length());
}

List<Map.Entry<String, Integer>> list = new LinkedList<Map.Entry<String, Integer>>( wordLength.entrySet() );

Collections.sort( list, new Comparator<Map.Entry<String, Integer>>()
{
public int compare( Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2 )
{
return (o1.getValue()).compareTo( o2.getValue() ) * -1;
}
} );

int countWords = 1;

for(Map.Entry<String, Integer> entry:list){
if(countWords <= 3){
System.out.println(entry.getKey());
}

countWords++;

}
}
}

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Q626. Write a Program to Sort entries of a map by its value

Ans. public class BuggyBread {
   public static void main(String args[]) {
      Map<String,Integer> wordLength = new HashMap();

      String str = "We are what we repeatedly do; excellence, then, is not an act but a habit";

      for(String word: str.split(" ")){
            wordLength.put(word, word.length());
      }

      List<Map.Entry<String, Integer>> list = new LinkedList<Map.Entry<String, Integer>>( wordLength.entrySet() );

      Collections.sort( list, new Comparator<Map.Entry<String, Integer>>()
{
public int compare( Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2 )
{
return (o1.getValue()).compareTo( o2.getValue() ) * -1;
}
} );

      System.out.println(list);

   }
}

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Q627. Write a Program to remove all spaces in a String

Ans. public class BuggyBread {
   public static void main(String args[]) {

      String str = "We are what we repeatedly do; excellence, then, is not an act but a habit";

      System.out.println(str.replaceAll(" ", ""));
   }
}

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Q628. Write a Program to remove multiple spaces

For example

We are what we repeatedly do; excellence, then, is not an act but a habit

should result in

We are what we repeatedly do; excellence, then, is not an act but a habit

Ans. public class BuggyBread {
   public static void main(String args[]) {
      String str = "We are what we repeatedly do; excellence, then, is not an act but a habit";

      String[] splittedString = str.split(" ");

      for(String word: splittedString){
         word = word.trim();
         if(!word.equals("")){
            System.out.print(word.trim());
            System.out.print(" ");
         }
      }


   }
}

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Q629. What are the ways to Reuse Code in Java ?

Ans. 1. Object Level Reuse - private methods
2. Class Level Reuse - static methods
3. package level Reuse - default methods
4. Application Level Reuse - Classes
5. Multiple Applications Level Reuse - Libraries , Frameworks

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Q630. What are the different primitive data types in Java ?

Ans. boolean
byte
char
double
float
int
long
short
void

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Q631. What are the different operators in Java ?

Ans. && - AND
|| - OR
! - LOGICAL NOT

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Q632. Write a Program to check if a number is perfect or not

Ans. public class BuggyBread {
   public static void main(String args[]) {
       int number = 7;
       boolean perfectNumber = true;
       for(int x=2;x<number;x++){
          if(number % x == 0){
             perfectNumber = false;
          }
       }

       if(perfectNumber){
          System.out.println("Perfect Number");
       } else {
          System.out.println("Not a Perfect Number");
       }
   }
}

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Q633. Write a Program to print all perfect numbers from 1 to 100

Ans. public class BuggyBread {
   public static void main(String args[]) {
      for(int number=1;number < 100;number++){
          boolean perfectNumber = true;
          for(int x=2;x<number;x++){
             if(number % x == 0){
                perfectNumber = false;
             }
          }

          if(perfectNumber){
             System.out.println(number);
          }
       }
   }
}

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Q634. What is a method reference in Java ?

Ans. Introduced with java 8 , Method References help us to point to methods by their name.

A method references is described using :: symbol

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Q635. Write a Program to print index of first capital character in a string.

Ans. public class BuggyBread {
   public static void main(String args[]) {
       String str = "we are what we repeatedly do excellence, then, is not an Act but a habit";
       int count = 1;
       for(Character c: str.toCharArray()){
          if(Character.isUpperCase(c)){
             break;
          } else {
             count++;
          }
       }

       System.out.println(count);
   }
}

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Q636. Write a Program to count number of capital characters in a String

Ans. public class BuggyBread {
   public static void main(String args[]) {
       String str = "We are what we repeatedly do excellence, then, is not an Act but a habit";
       int count = 0;
       for(Character c: str.toCharArray()){
          if(Character.isUpperCase(c)){
             count++;
          }
       }

       System.out.println(count);
   }
}

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Q637. Write a Program to count number of lower case characters in a String

Ans. public class BuggyBread1 {
   public static void main(String args[]) {
       String str = "We are what we repeatedly do excellence, then, is not an Act but a habit";
       int count = 0;
       for(Character c: str.toCharArray()){
          if(Character.isLowerCase(c)){
             count++;
          }
       }

       System.out.println(count);
   }
}

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Q638. Write a Program to print first word with a capital character in a String

Ans. public class BuggyBread {
   public static void main(String args[]) {
       String str = "we are what we repeatedly do excellence, then, is not an act but a haBit";
       String wordWithCaptalChar = "";

       for(String word:str.split(" ")){
          if(!word.equals(word.toLowerCase())){
             wordWithCaptalChar = word;
          }
       }

       System.out.println(wordWithCaptalChar);
   }
}

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Q639. Write a Program to print the word in a String starting with a capital character

Ans. public class BuggyBread {
   public static void main(String args[]) {
       String str = "we are what we repeatedly Do excellence, then, is not an act but a haBit";
       String wordWithFirstCaptalChar = "";

       for(String word:str.split(" ")){
          if(Character.isUpperCase(word.charAt(0))){
             wordWithFirstCaptalChar = word;
          }
       }

       System.out.println(wordWithFirstCaptalChar);
   }
}

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Q640. Write a Program to count number of words in a String

Ans. public class BuggyBread1 {
   public static void main(String args[]) {
       String str = "we are what we repeatedly Do excellence, then, is not an act but a haBit";

       System.out.println(str.split(" ").length);
   }
}

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