CSC212 Lab 2 2014

--D. Thiebaut (talk) 10:53, 9 September 2014 (EDT)

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Problem 1: playing with ints and doubles

• Write a Java program that contains 3 ints and displays the sum of the 3 ints.
• Modify your program so that it creates 3 doubles and displays their products.

Problem 2: Strings

• Write a java program with a function called printBox(). The function receives a string as an argument, and displays the string between 2 lines of stars. For example:

String name = "Smith College";

printBox( name );

will print something like this:

*********************************
Smith College
*********************************

Note that the length of the lines of stars is fixed.

Problem 3: Loops

• Write a Java program that displays all the integers from -10 to +10, one per line.
• Write a Java program that displays all the positive multiples of 3 less than 30, starting with 3.
• Write a Java program that displays all the positive multiples of 3 less than 30, starting with 0.
• Write a Java program that displays all the negative multiples of 5 greater than -40.
• Write a Java program that displays all the powers of 2 less than a million, starting with 2.
• Write a Java program that prints the first 10 positive multiples of 3 and of 5, two per line, as shown below:

 3 5
 6 10
 9 15
 ...

• Write a Java program that where the function printBox() seen before actually puts a box around the string it prints. In order to get the length of the string received, the function can do this:

        int n = name.length();  // name is the string

Also, if you use System.out.print() instead of System.out.println(), you can put many strings/chars on the same line without going to the next line...

Problem 4: If statements

• Write a Java program that prints only the multiples of 3, 5 and 7 that are less than 500. To find if a variable n is divisible by 3, for example, you can do this:

if ( n % 3 == 0 ) {
     // n is a multiple of 3
}
else {
     // n is not a multiple of 3
}

• Write a java program that contains a function called min3( int a, int b, int c ) that returns the smallest of 3 integers. Test it on 3 different variables.
• Modify the same Java program, and add a new function called min3( double a, double b, double c ) that returns the smallest of 3 doubles. Verify that the java compiler does not complain about two functions/methods with the same name. As long as their list of parameters are different, Java is fine with it.

Problem 5: While loops

• Redo the questions of Problem 3 above, but using while loops only this time.

Submission to Moodle

• Submit the Java program that prints a boxed string to Moodle.
• Make sure you call the class for this program: Lab2, and save it a file called Lab2.java.
• You can follow the directions for submitting this program for automatic grading on Moodle here.