Java Programming

Java Programming

Operators and Assignments has 21 Questions
What will be the output of the program?
class PassA 
{
    public static void main(String [] args) 
    {
        PassA p = new PassA();
        p.start();
    }

    void start() 
    {
        long [] a1 = {3,4,5};
        long [] a2 = fix(a1);
        System.out.print(a1[0] + a1[1] + a1[2] + " ");
        System.out.println(a2[0] + a2[1] + a2[2]);
    }

    long [] fix(long [] a3) 
    {
        a3[1] = 7;
        return a3;
    }
}

12 15
15 15
3 4 5 3 7 5
3 7 5 3 7 5
which two of the following statements, inserted independently, could legally be inserted into missing section of this code?
    
import java.awt.*;
class Ticker extends Component 
{
    public static void main (String [] args) 
    {
        Ticker t = new Ticker();
        /* Missing Statements ? */
    }
}
  1. boolean test = (Component instanceof t);
  2. boolean test = (t instanceof Ticker);
  3. boolean test = t.instanceof(Ticker);
  4. boolean test = (t instanceof Component);

1 and 4
2 and 3
1 and 3
2 and 4
What will be the output of the program?
class Test 
{
    public static void main(String [] args) 
    {
        Test p = new Test();
        p.start();
    }

    void start() 
    {
        boolean b1 = false;
        boolean b2 = fix(b1);
        System.out.println(b1 + " " + b2);
    }

    boolean fix(boolean b1) 
    {
        b1 = true;
        return b1;
    }
}

true true
false true
true false
false false
Which of the following are legal lines of code?
  1. int w = (int)888.8;
  2. byte x = (byte)1000L;
  3. long y = (byte)100;
  4. byte z = (byte)100L;

1 and 2
2 and 3
3 and 4
All statements are correct.
What will be the output of the program?
class PassS 
{
    public static void main(String [] args) 
    {
        PassS p = new PassS();
        p.start();
    }

    void start() 
    {
        String s1 = "slip";
        String s2 = fix(s1);
        System.out.println(s1 + " " + s2);
    }

    String fix(String s1) 
    {
        s1 = s1 + "stream";
        System.out.print(s1 + " ");
        return "stream";
    }
}

slip stream
slipstream stream
stream slip stream
slipstream slip stream
Which two statements are equivalent?
  1. 16*4
  2. 16>>2
  3. 16/2^2
  4. 16>>>2

1 and 2
2 and 4
3 and 5
1 and 3
What will be the output of the program?
class BitShift 
{
    public static void main(String [] args) 
    {
        int x = 0x80000000;
        System.out.print(x + " and  ");
        x = x >>> 31;
        System.out.println(x);
    }
}

-2147483648 and 1
0x80000000 and 0x00000001
-2147483648 and -1
1 and -2147483648
Which two statements are equivalent?
  1. 3/2
  2. 3<2
  3. 3*4
  4. 3<<2

1 and 2
2 and 3
3 and 4
1 and 4
What will be the output of the program?
class Equals 
{
    public static void main(String [] args) 
    {
        int x = 100;
        double y = 100.1;
        boolean b = (x = y); /* Line 7 */
        System.out.println(b);
    }
}

true
false
Compilation fails
An exception is thrown at runtime
which three statements are true?
import java.awt.Button;
class CompareReference 
{
    public static void main(String [] args) 
    {
        float f = 42.0f;
        float [] f1 = new float[2];
        float [] f2 = new float[2];
        float [] f3 = f1;
        long x = 42;
        f1[0] = 42.0f;
    }
}
  1. f1 == f2
  2. f1 == f3
  3. f2 == f1[1]
  4. x == f1[0]
  5. f == f1[0]

1, 2 and 3
2, 4 and 5
3, 4 and 5
1, 4 and 5
What will be the output of the program?
class Test 
{
    public static void main(String [] args) 
    {
        int x=20;
        String sup = (x < 15) ? "small" : (x < 22)? "tiny" : "huge";
        System.out.println(sup);
    }
}

small
tiny
huge
Compilation fails
Which two are equal?
  1. 32/4
  2. (8 >> 2) << 4
  3. 2^5
  4. 128 >>> 2
  5. 2 >> 5

1 and 2
2 and 4
1 and 3
2 and 3
What will be the output of the program?
class Test 
{
    public static void main(String [] args) 
    {
        int x= 0;
        int y= 0;
        for (int z = 0; z < 5; z++) 
        {
            if (( ++x > 2 ) && (++y > 2)) 
            {
                x++;
            }
        }
        System.out.println(x + " " + y);
    }
}

5 2
5 3
6 3
6 4
What will be the output of the program?
class Test 
{
    public static void main(String [] args) 
    {
        int x= 0;
        int y= 0;
        for (int z = 0; z < 5; z++) 
        {
            if (( ++x > 2 ) || (++y > 2)) 
            {
                x++;
            }
        }
    System.out.println(x + " " + y);
    }
}

5 3
8 2
8 3
8 5
What will be the output of the program?
class Bitwise 
{
    public static void main(String [] args) 
    {
        int x = 11 & 9;
        int y = x ^ 3;
        System.out.println( y | 12 );
    }
}

0
7
8
14
What will be the output of the program?
class SSBool 
{
    public static void main(String [] args) 
    {
        boolean b1 = true;
        boolean b2 = false;
        boolean b3 = true;
        if ( b1 & b2 | b2 & b3 | b2 ) /* Line 8 */
            System.out.print("ok ");
        if ( b1 & b2 | b2 & b3 | b2 | b1 ) /*Line 10*/
            System.out.println("dokey");
    }
}

ok
dokey
ok dokey
No output is produced
What will be the output of the program?
class SC2 
{
    public static void main(String [] args) 
    {
        SC2 s = new SC2();
        s.start();
    }

    void start() 
    {
        int a = 3;
        int b = 4;
        System.out.print(" " + 7 + 2 + " ");
        System.out.print(a + b);
        System.out.print(" " + a + b + " ");
        System.out.print(foo() + a + b + " ");
        System.out.println(a + b + foo());
    }

    String foo() 
    {
        return "foo";
    }
}

9 7 7 foo 7 7foo
72 34 34 foo34 34foo
9 7 7 foo34 34foo
72 7 34 foo34 7foo
What will be the output of the program?
class Test 
{
    static int s;
    public static void main(String [] args) 
    {
        Test p = new Test();
        p.start();
        System.out.println(s);
    }

    void start() 
    {
        int x = 7;
        twice(x);
        System.out.print(x + " ");
    }

    void twice(int x) 
    {
        x = x*2;
        s = x;
    }
}

7 7
7 14
14 0
14 14
What will be the output of the program?
class Two 
{
    byte x;
}

class PassO 
{
    public static void main(String [] args) 
    {
        PassO p = new PassO();
        p.start();
    }

    void start() 
    {
        Two t = new Two();
        System.out.print(t.x + " ");
        Two t2 = fix(t);
        System.out.println(t.x + " " + t2.x);
    }

    Two fix(Two tt) 
    {
        tt.x = 42;
        return tt;
    }
}

null null 42
0 0 42
0 42 42
0 0 0
What will be the output of the program?
class BoolArray 
{
    boolean [] b = new boolean[3];
    int count = 0;

    void set(boolean [] x, int i) 
    {
        x[i] = true;
        ++count;
    }

    public static void main(String [] args) 
    {
        BoolArray ba = new BoolArray();
        ba.set(ba.b, 0);
        ba.set(ba.b, 2);
        ba.test();
    }

    void test() 
    {
        if ( b[0] && b[1] | b[2] )
            count++;
        if ( b[1] && b[(++count - 2)] )
            count += 7;
        System.out.println("count = " + count);
    }
}

count = 0
count = 2
count = 3
count = 4
What will be the output of the program?
public class Test 
{ 
    public static void leftshift(int i, int j) 
    {
        i <<= j; 
    } 
    public static void main(String args[]) 
    {
        int i = 4, j = 2; 
        leftshift(i, j); 
        System.out.printIn(i); 
    } 
}

2
4
8
16