Click to See Complete Forum and Search --> : could someone check over these ansers?


susancbk
09-23-2004, 10:07 PM
Im taking a intro to alogorithm design class. I was going over my study sheet for my first exam and just wanted to make sure my answers were correct before I study something that was wrong anyone have any input/suggestions/corrections i'd really appreciate it


Write a statement that declares an integer variable
int hoursWorked = 3 ;

Write a statement that declares a String reference variable

String name = “bob”;

Write a statement that declares a character variable storing an ‘a’

char letter = ‘a’;

Write a statement that declares a String object storing the character sequence “hello friend”.

String greeting = “hello friend” ;

Write a statement that declares a Scanner object that references the standard input stream.

Scanner stdin = newScanner(System.in);

Write a statement that reads an integer from the standard input stream (assuming it has been declared as in the last statement)
int hours = stdin.nextInt();

Write a single Java statement that outputs your first name onto the monitor (standard output stream) and your last name on the following line.

System.out.print(“Susan \n Buck”);


Write a Java program to compute and display the product of two integers.

//Author: Susan Buck

public class product {

public static void main(String[]args) {

int A = 2 ;
int B = 3 ;
int calc = A * B ;

System.out.print(“The product of” + A + “and” + B + “is” + calc) ;

}
}

Write a Java program to compute and display the area of a rectangle.

//Author: Susan Buck

public class rectangle {

public static void main (String[]args) {

int topbot = 4 ;
int sides = 2 ;
int area = top * side ;

System.out.print (“The area of a triangle with a top and bottom of” + topbot + “inches, and sides of” + sides + “inches, has an area of” + area) ;

}
}

Write a Java program to compute and display the location of all occurrences of “ssi” in the word Mississippi.

//Author: Susan Buck

public class state

public static void main (String[]args) {

String count = “mississippi” ;
String searchString = “ssi” ;
int n1 = count.indexOf(searchString,1) ;
int n2 = count.indexOf(searchString, n1 + 2) ;

System.out.print(“The letters ssi occurs at positions” + n1 + “and” + n2 + “in the word Mississippi”)

}
}

ray326
09-23-2004, 10:39 PM
That generally looks ok so here are some random comments. Some of the problems may be a bit tricky, e.g. the difference between a String reference and a String object. In one case the teacher may be looking for

String greeting = new String("hello friend");

rather than a simple initialization assignment.

Also keep in mind that object names begin with a lower case letter while class names are caplitalized. This is not a requirement of the compiler but it *is* the OO standard way of doing things. So A and B aren't really good names.

What if you didn't know ahead of time that Mississippi had exactly two occurances of "ssi"? That makes for a more "interesting" problem. :)

buntine
09-23-2004, 11:01 PM
Also, you will want to add some spaces in your string concatenation. Otherwise, it will look like this: "The product of2and3is5". You may want to use println instead of print as it will automatically place a newline character at the end of the string.

System.out.println(“The product of ” + A + “ and ” + B + “ is ” + calc) ;

Regards.

Khalid Ali
09-24-2004, 12:18 AM
I am sure its a typo but still worth a pointer, this line below
Scanner stdin = newScanner(System.in);
should be
Scanner stdin = new Scanner(System.in);

to decalre an instance of an object you usually use "new" keyword.