Stings, Cloning and ArrayList

Which of this method of class StringBuffer is used to concatenate the string representation to the end of invoking string?

• concat()

• append()

• join()

• concatenate()

What will be the output of the following Java program?

class output

{

public static void main(String args[])

{

String a = "hello i love java"; System.out.println(a.indexOf('e')+" "+a.indexOf('a')+" "+a.lastIndexOf('l')+" "+a.lastIndexOf('v'));

}

}

• 6 4 6 9

• 5 4 5 9

• 7 8 8 9

• 1 14 8 15

What will be the output of the following Java code?

class output {

public static void main(String args[])

{

StringBuffer sb=new StringBuffer("Hello"); sb.replace(1,3,"Java");

System.out.println(sb);

} }

• Hello java

• Hellojava

• HJavalo

• Hjava

What will be the output of the following Java code?

class output

{

public static void main(String args[])

{

StringBuffer s1 = new StringBuffer("Hello World"); s1.insert(6 , "Good ");

System.out.println(s1);

} }

• HelloGoodWorld

• HellGoodoWorld

• HellGood oWorld

• Hello Good World

Which of these method of Object class can clone an object?

• Objectcopy()

• copy()

• Object clone()

• None of the above

Which of these class can generate an array which can increase and decrease in size automatically?

• ArrayList()

• DynamicList()

• LinkedList()

• MallocList()

Which of these method can be used to increase the capacity of ArrayList object manually

• Capacity()

• increaseCapacity()

• increasecapacity()

• ensureCapacity()

Which of these methods can be used to obtain a static array from an ArrayList object?

• Array()

• covertArray()

• toArray()

• convertoArray()

What will be the output of the following Java program?

import java.util.*;

class Arraylist

{

public static void main(String args[])

{

ArrayList obj = new ArrayList();

obj.add("A");

obj.add("B");

obj.add("C");

obj.add(1, "D");

System.out.println(obj);

} }

• [A, B, C, D]

• [A, D, B, C]

• [A, D, C]

• [A, B, C]

What will be the output of the following Java program?

import java.util.*;

class Output

{

public static void main(String args[])

{

ArrayList obj = new ArrayList();

obj.add("A");

obj.ensureCapacity(3);

System.out.println(obj.size()); } }

• 1

• 2

• 3

• 4