java lang and java io Mcqs
Our collections of Multiple choice questions and answers focuses on study of java lang and java io. These questions are chosen from a collection of most authoritative and best reference books on Java. Our aim is to prepare an individual for competitive exams like NTS, GAT, ECAT, University and College entrance exams and various tests and job interviews. One should practice our Mcqs to assimilate java lang and java io topic comprehensively.
Java Programming Mcqs
Computer MCQS
Sciences MCQS
2.
Which of the following methods is a method of wrapper Integer for obtaining hash code for the invoking object?
3.
Which of these is a super class of wrappers Long, Character & Integer?
4.
Which of these is a wrapper for simple data type char?
5.
Which of the following is method of wrapper Integer for converting the value of an object into int?
6.
Which of these methods is used to obtain value of invoking object as a long?
7.
What is the output of this program?
class Output
{
public static void main(String args[])
{
char a[] = {'a', '5', 'A', ' '};
System.out.print(Character.isDigit(a[0]) + " ");
System.out.print(Character.isWhitespace(a[3]) + " ");
System.out.print(Character.isUpperCase(a[2]));
}
}
class Output
{
public static void main(String args[])
{
char a[] = {'a', '5', 'A', ' '};
System.out.print(Character.isDigit(a[0]) + " ");
System.out.print(Character.isWhitespace(a[3]) + " ");
System.out.print(Character.isUpperCase(a[2]));
}
}
8.
What is the output of this program?
class Output
{
public static void main(String args[])
{
Integer i = new Integer(257);
byte x = i.byteValue();
System.out.print(x);
}
}
class Output
{
public static void main(String args[])
{
Integer i = new Integer(257);
byte x = i.byteValue();
System.out.print(x);
}
}
10.
Which of the following method of Process class can terminate a process?
12.
Which of these class can encapsulate an entire executing program?
13.
Which of the following is method of System class is used to find how long a program takes to execute?
14.
Which of these class holds a collection of static methods and variables?
15.
What is the output of this program?
class Output
{
public static void main(String args[])
{
long start, end;
start = System.currentTimeMillis();
for (int i = 0; i < 10000000; i++);
end = System.currentTimeMillis();
System.out.print(end - start);
}
}
class Output
{
public static void main(String args[])
{
long start, end;
start = System.currentTimeMillis();
for (int i = 0; i < 10000000; i++);
end = System.currentTimeMillis();
System.out.print(end - start);
}
}
16.
What is the output of this program?
class Output
{
public static void main(String args[])
{
byte a[] = { 65, 66, 67, 68, 69, 70 };
byte b[] = { 71, 72, 73, 74, 75, 76 };
System.arraycopy(a , 0, b, 0, a.length);
System.out.print(new String(a) + " " + new String(b));
}
}
class Output
{
public static void main(String args[])
{
byte a[] = { 65, 66, 67, 68, 69, 70 };
byte b[] = { 71, 72, 73, 74, 75, 76 };
System.arraycopy(a , 0, b, 0, a.length);
System.out.print(new String(a) + " " + new String(b));
}
}