Question1:
1.1 Explain the difference between using a computer program and programming a computer.
1.2 How do you discover syntax errors? How do you discover logic errors?
1.3 What is the difference between object and object reference?
1.4 Explain the difference between an object and a class.
1.5 What is the difference between equality and assignment?
1.6 What is the difference between a reserved word and an identifier?
1.7 What is the implicit parameter? Explain with example.
1.8 Write a java statement to convert a string str to a double.
Question 2
2.1 Which of the following are legal identifiers? why?
Greeting1
g
void
104IT
IT104
Hello, World
Hello3World
2.2 Construct a logical expression to represent each of the following conditions:
a. x is between 3 and 15 but not equal to 10.
b. x is between 10 and 20 but not odd.
c. y is divisible by 5 but not by 40.
d. str is a lowercase or uppercase letter.
2.3 What is the difference between the following two statements?
a. if (n > 2) { if (n < 6) System.out.println("Done!"); }
else System.out.println("Error");
b. if (n > 2) { if (n < 6) System.out.println("Done!");
else System.out.println("Error"); }
2.4 What is the difference between the result of the following two statements?
a. int cents = (int)(100 * price + 0.5);
b. int cents = (100 * price + 0.5);
Question 3
3.1 Write an Algorithm to decide which is cheaper car or bus for a travel:
You want to decide whether you should drive your car to work or take the bus. You know the one-way distance from your home to your place of work, and the fuel efficiency of your car (in miles per gallon). You also know the one-way price of a train ticket. You assume the cost of gas at $4 per gallon, and car maintenance at 5 cents per mile. Write an algorithm to decide which commute is cheaper.
omplete the following program so that it to c only Use string concatenation3.2 prints the message "the quick white tiger jumps over the small dog". public class ConcatDemo { public static void main(String[] args) { String animal1 = "quick white tiger"; String animal2 = "small dog";
String article = "the"; String action = "jumps over"; /* Your work goes here */
System.out.println(message); } }
3.3 Find the output of the following code when the user enters 100 and when the user enters AQ:
public static void main(String[] args)
{
Scanner in = new Scanner(System.in);
System.out.print("Enter somthing: ");
String str = in.next();
int count = Integer.parseInt(str);
System.out.println("Input is " + count);
}
Question 4
4.1 Write a program that simulates a simple calculator. It reads two integers and a character. If the character is a +, the sum is printed; if it is a -, the difference is printed; if it is a *, the product is printed; if it is a /, the quotient is printed; and if it is a %, the remainder is printed.
4.2 In the 2- dimensional plane, a point is described by its two coordinates x and y. It supports these operations :
A constructor allowing initialization of both coordinates
Accessors and mutators to its coordinates
Translation of a point
a. Write a java class, called MyPoint, that corresponds to such an abstraction of points in the dimensional plane.
b. Provide a tester class that creates one point, then translates and displays its new coordinates.