Question1: What is the result of below program?
public class TestVariables {
int x,y;
public TestVariables(int x,int y) {
intialize(x,y);
}
public void intialize(int x,int y) {
this.x = x*x;
this.y=y*y;
}
public static void main(String[] args) {
int x=3,y=5;
TestVariables test = new TestVariables(x,y);
System.out.println(x+ " "+y);
}
}
A. Compilation fails.
B. 3 5
C. 0 0
D. 9 25
Answer: B
Question2: What is the result of the below program?
public class SwitchTest {
public static void main(String[] args) {
int wd=0;
String days[] = {"sun","mon","wed","sat"};
for(String s:days) {
switch(s) {
case "sat":
case "sun":
wd-=1;
break;
case "mon":
wd++;
case "wed":
wd+=2;
}
}
System.out.println(wd);
}
}
A. 3
B. 4
C. -1
D. Compilation fails.
Answer: A
Question3: Given below program:
public class MyFile {
public static void main(String[] args) {
String arg1 = args[1];
String arg2 = args[2];
String arg3 = args[3];
System.out.println("Arg is"+arg3);
}
}
Which command-line arguments should you pass to the program to obtain the following output? Arg is 2
A. java MyFile 1 3 2 2
B. java MyFile 2 2 2
C. java MyFile 1 2 2 3 4
D. java MyFile 0 1 2 3
Answer: A
Question4: Given below code :
StringBuilder sb1 = new StringBuilder();
String str1 = sb1.toString();
// Insert Code Here
System.out.println(str1 == str2);
Which code fragment, when inserted at line 9, enables the code to print true?
A. String str2 = str1;
B. String str2 = new String(str1);
C. String str2 = sb1. toString();
D. String str2 = “Duke”;
Answer: A
Question5: Given the below program:
public class TestCal {
public void updatePrice(Product product,double price) {
price = price *2;
product.price = product.price + price;
}
public static void main(String[] args) {
Product product = new Product();
product.price = 200;
double price = 100;
TestCal test = new TestCal();
test.updatePrice(product, price);
System.out.println(product.price+":"+price);
}
}
What is the result?
A. 200.0 : 100.0
B. 400.0 : 200.0
C. 400.0 : 100.0
D. Compilation fails.
Answer: C
Question6: Given the below
public class Test {
public static void main(String[] args) {
boolean a = new Boolean(Boolean.valueOf(args[0]));
boolean b = new Boolean(args[1]);
System.out.println(a + "" + b);
}
}
javac Test.java
java Test 1 null
What is the result?
A. 1 null
B. true false
C. false false
D. true true
E. A ClassCastException is thrown at runtime.
Answer: C
