Java Basics MCQ 2nd | Java Basics Question Answers, JAVA Test

What is essential in making sure that your loop is not infinite ?

What displays from the following statements? String word = “abcde”; for (int i = 0; i <4; i+=2) System.out.print(word[i]);

Which is NOT a section of all types of loops ?

What is a loop ?

Can you compare a boolean to an integer?

Primitive datatypes are allocated on a stack.

Following code will result in: int a1 = 5; double a2 = (float)a1;

Java runs on _______.

What is the size of a Char in Java?

A null reference may be used to access a static variable or method.

What gets printed when the following code is compiled and run with the following command – java test 2 Select the one correct answer.

public class test {
public static void main(String args[]) {
Integer intObj=Integer.valueOf(args[args.length-1]);
int i = intObj.intValue();

if(args.length > 1)
System.out.println(i);
if(args.length > 0)
System.out.println(i – 1);
else
System.out.println(i – 2);
}
}

Which of the following statements is false about objects?

Which of these are legal identifiers. Select the three correct answers.
a. number_1
b. number_a
c. $1234
d. -volatile

The class Hashtable is used to implement which collection interface. Select the one correct answer.

TreeMap class is used to implement which collection interface. Select the one correct answer.

Given a one dimensional array arr, what is the correct way of getting the number of elements in arr. Select the one correct answer.

What happens when the following code is compiled and run. Select the one correct answer.

for(int i = 1; i < 3; i++)
for(int j = 3; j > i; j–)
assert i!=j {System.out.println(i); }

What gets displayed on the screen when the following program is compiled and run. Select the one correct answer.

protected class example {
public static void main(String args[]) {
String test = “abc”;
test = test + test;
System.out.println(test);
}
}

In the following class definition, which is the first line (if any) that causes a compilation error. Select the one correct answer.

public class test {
public static void main(String args[]) {
char c;
int i;
c = ‘A’; // 1
i = c; //2
c = i + 1; //3
c++; //4
}
}

Which of the following is a Java keyword. Select the four correct answers.
a. extern
b. synchronized
c. volatile
d. friend
e. friendly
f. transient
g. this
h. then