12)
class C{
static String m(int i) {return "int";}
static String m(float i) {return "float";}
public static void main (String[] args) {
long a1 = 1; double b1 = 2;
System.out.print(m(a1)+","+ m(b1));
}}
Prints: float,double
Prints: float,float
Prints: double,float
Compile-time error
None of the above
Explanation:
No Explanation Available
Ans: 4
13)
class C
{
public static void main(String a[])
{
C c1=new C();
C c2=m1(c1);
C c3=new C();
c2=c3; //6
anothermethod();
}
static C m1(C ob1){
ob1 =new C();
return ob1;
}
}
After line 6, how many objects are eligible for garbage collection?
Ans: 1
Ans: 2
Ans: 3
Ans: 4
None of the above
Explanation:
No Explanation Available
Ans: 2
14)
1. StringBuffer s1 = new StringBuffer("abc");
2. StringBuffer s2 = s1;
3. StringBuffer s3 = new StringBuffer("abc");
How many objects are created ?
0
Ans: 1
Ans: 2
Ans: 3
Explanation:
No Explanation Available
Ans: 4
15)
class c2
{
{
System.out.println("initializer");
}
public static void main(String a[])
{
System.out.println("main");
c2 ob1=new c2();
}
}
prints main and initializer
prints initializer and main
compile time error
None of the above
Explanation:
No Explanation Available
Ans: 1
16)
class c1
{
public static void main(String a[])
{
c1 ob1=new c1();
Object ob2=ob1;
System.out.println(ob2 instanceof Object);
System.out.println(ob2 instanceof c1);
}
}
Prints true,false
Print false,true
Prints true,true
compile time error
None of the above
Explanation:
No Explanation Available
Ans: 3
17)
class A extends Thread {
private int i;
public void run() {i = 1;}
public static void main(String[] args) {
A a = new A();
a.run();
System.out.print(a.i);
}}
Prints nothing
Prints: 1
Prints: 01
Compile-time error
None of the above
Explanation:
a.run() method was called instead of a.start(); so the full program runs as a single thread so a.run() is guaranteed to complete
Ans: 2
18)
class bike
{
}
class arr extends bike{
public static void main(String[] args) {
arr[] a1=new arr[2];
bike[] a2;
a2=a1; //3
arr[] a3;
a3=a1; //5
}}
compile time error at line 3
compile time error at line 5
Runtime exception
The code runs fine
None of the above
Explanation:
bike is the superclass of arr.so they are compatible(superobject=subobject)
but subobject=superobject not allowed
Ans: 4
19)
class C{
public static void main (String[] args) {
String s1="hjhh"; // 1
String s2="\u0002"; //2
String s3="'\\'"; //3
}}
compile time error at line 1
compile time error at line 2
compile time error at line 3
Runtime exception
the code runs without any error
Explanation:
A String literal is a sequence of characters enclosed in double quotes
Ans: 5
20)
Which data type is wider for the purpose of casting: float or long?
float
long
Explanation:
float is wider than long, because the entire range of long fits within the range of float.
Ans: 1
