UNIVERSITY OF ENGINEERING AND TECHNOLOGY, TAXILA
FACULTY OF TELECOMMUNICATION AND INFORMATION ENGINEERING
SOFTWARE ENGINEERING DEPARTMENT
LAB 04
Operators and Arrays
Operators
1. What is the value of i after executing the following code segments? Assume that the variables
have been initialized to i = 21, j = 42 and k = 11; Justify your answer.



i = 4 * (j + 16) % k
i=i-j+k*7
i = (i - j + k) * 7
2. What do each of the following print?

System.out.println(2 + "bc");

System.out.println(2 + 3 + "bc");

System.out.println((2+3) + "bc");

System.out.println("bc" + (2+3));

System.out.println("bc" + 2 + 3);

Explain each outcome.
3. Evaluate the expression 29+27*2/3-40.Store the result in int type variable named total.
4. Try it and see. -47 / 5 = -9 and -47 % 5 = -2. The quotient is always rounded toward zero.
5. Suppose that a and b are boolean values. Show that the expression (!(a && b) && (a || b)) ||
((a && b) || !(a || b)) is equivalent to true.
6. Try evaluating following expressions and print each result:

Int a=7;

Int b=6;
Object Oriented Programming
3rd Semester-SE
UET Taxila
UNIVERSITY OF ENGINEERING AND TECHNOLOGY, TAXILA
FACULTY OF TELECOMMUNICATION AND INFORMATION ENGINEERING
SOFTWARE ENGINEERING DEPARTMENT

int c=a-b;

int d=a&b;

int e=a^b;

int f=(~a & b) |(a & ~b);

int g=~a &0x0f;

int e=~a & 0xf2;

byte Shft1=64,Shft2=0;

int i=Shft1<<2;

Shft2=(byte)(Shft1<<2);

byte Shft3=0xf1;

System.out.println(hex[Shft>>4]& 0xf1]);
Suppose int a= -1;

int b=a>>24;

a=a>>>24;
suppose b=1 and c=1;

a>>(b+3)

a|4+c>>b&5;

(a|(((4+c)>>b &7))’
7. Suppose that a and b are int values. Simplify the following expression: (!(a < b) && !(a > b))
8. Suppose that a variable a is declared as int a = 2147483647 (or equivalently,
Integer.MAX_VALUE). What do each of the following print?

System.out.println(a);
Object Oriented Programming
3rd Semester-SE
UET Taxila
UNIVERSITY OF ENGINEERING AND TECHNOLOGY, TAXILA
FACULTY OF TELECOMMUNICATION AND INFORMATION ENGINEERING
SOFTWARE ENGINEERING DEPARTMENT

System.out.println(a + 1);

System.out.println(2 - a);

System.out.println(-2 - a);

System.out.println(2 * a);

System.out.println(4 * a);

Explain each outcome.
9. Suppose that a variable a is declared as double a = 3.14159. What do each of the following
print?

System.out.println(a);

System.out.println(a + 1);

System.out.println(8 / (int) a);

System.out.println(8 / a);

System.out.println(8 / a);

System.out.println((int) (8 / a);

Explain each outcome.
10. Write a program that takes two positive integers as command-line arguments and prints true if
either evenly divides the other.
11. Give the value of a after the execution of each of the following sequences:
int a = 1;
a = a + a;
a = a + a;
a = a + a;
boolean a = true; int a = 2;
a = !a;
a = a * a;
a = !a;
a = a * a;
a = !a;
a = a * a;
Explain each outcome
Arrays
Try to grasp the concept of Arrays with the help of following code.
Object Oriented Programming
3rd Semester-SE
UET Taxila
UNIVERSITY OF ENGINEERING AND TECHNOLOGY, TAXILA
FACULTY OF TELECOMMUNICATION AND INFORMATION ENGINEERING
SOFTWARE ENGINEERING DEPARTMENT
public class Array_1{
public static void main(String args[]){
int val[]=new int[10];
for (int i=0;i<10;i++)
{
val[i]=i;
System.out.println(val[i]);
}
}
12. What does the following code fragment print?
int [] a = new int[10];
for (int i = 0; i < 10; i++)
a[i] = 9 - i;
for (int i = 0; i < 10; i++)
a[i] = a[a[i]];
for (int i = 0; i < 10; i++)
System.out.println(a[i]);
13. What values does the following code put in the array a?
N = 10;
int[] a = new int[N];
a[0] = 0;
a[1] = 1;
for (int i = 0; i < N; i++)
a[i] = a[i-1] + a[i-2];
System.out.println(a[i]);
14. What does the following code fragment print?
int[] a = { 1, 2, 3 };
int[] b = { 1, 2, 3 };
System.out.println(a == b);
15. What happens when you try to compile a program with the following statement?
int[] a = new int[-17];
Task
1. Given the temperature t=32 (in Fahrenheit) and the wind speed v=100 (in miles per hour), the
National Weather Service defines the effective temperature (the wind chill) to be:
Object Oriented Programming
3rd Semester-SE
UET Taxila
UNIVERSITY OF ENGINEERING AND TECHNOLOGY, TAXILA
FACULTY OF TELECOMMUNICATION AND INFORMATION ENGINEERING
SOFTWARE ENGINEERING DEPARTMENT
W = 35.74 + 0.6215* t + (0.4275 *t - 35.75) v0.16
Prints out the wind chill
Hint:
Use Math.pow (a, b) = ab to compute v0.16. e.g Math.pow (v, 0.16)
2. Write a code fragment to transpose a square two-dimensional array in place without creating a
second array.
3. Write code fragments to create a two-dimensional array b[][] that is a copy of an existing twodimensional array a[][], under each of the following assumptions:
 a[][] is square
 a[][] is rectangular
 a[][] may be ragged
Ragged arrays. There is no requirement that all rows in a two-dimensional array have the same
length—an array with rows of nonuniform length is known as a ragged array. The possibility of
ragged arrays creates the need for more care in crafting array-processing code. For example, this
code prints the contents of a ragged array:
for (int i = 0; i < a.length) {
for (int j = 0; j < a[i].length; j++) {
System.out.print(a[i][j] + " ");
}
System.out.println();
}
Object Oriented Programming
3rd Semester-SE
UET Taxila