1. Which of these class is superclass of String and StringBuffer class?

1. 1. java.io

   
   
   

   2. ArrayList

   
   
   

   3. java.lang

   
   
   

   4. java.util

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   java.lang

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2. Which of this method of class String is used to obtain a length of String object?

1. 1. Sizeof()

   
   
   

   2. length()

   
   
   

   3. get()

   
   
   

   4. lengthof()

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   Method length() of string class is used to get the length of the object which invoked method length().

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3. Which of these operators can be used to concatenate two or more String objects?

1. 1. &

   
   
   

   2. +=

   
   
   

   3. ||

   
   
   

   4. +

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   Operator + is used to concatenate strings, Example String s = “i ” + “like ” + “java”; String s contains “I like java”.

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4. Which of these method of class String is used to extract a single character from a String object?

1. 1. chatat()

   
   
   

   2. charAt()

   
   
   

   3. ChatAt()

   
   
   

   4. CHARAT()

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   charAt()

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5. What is the output of this program?
   

   
   public class Result
     {
         public static void main(String[]args)
         {
             String[] array = { "for", "tea", "too" };
             String num= (array.length > 2) ? array[2]: null;
         }
     }
   

1. 1. The variable num is set to elements[0].

   
   
   

   2. The variable num is set to null

   
   
   

   3. An exception is thrown at run time

   
   
   

   4. Compilation error

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   The value at the 0th position will be assigned to the variable num.

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