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.
3.2 Use string concatenation only to complete the following program so that it 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