Practice 4: JavaBat

Posted: Wednesday, September 23.

JavaBat is a Web site allowing you to practice Java: After reading a relatively short problem and writing a solution, you can submit it to JavaBat to test your solution.

JavaBat's questions are posed in terms of writing methods, which is a concept that we haven't seen yet, but it's easy enough to explain. Below is an example of a method that I've written.

public int distanceBetween(int a, int b) {
    int diff;
    if (a > b) {
        diff = a - b;
    } else {
        diff = b - a;
    }
    return diff;
}

As seen in the first line, here we are writing a method named distanceBetween that computes an integer. As seen in the parentheses, this method has two inputs (also known as parameters) named a and b. The method performs some computation and when it has determined its answer, we use a return statement, as illustrated above.

JavaBat has many problems, but I've picked out a few and written some others that I think are particularly good practice for now.

Chapter 4: Using Numbers
243564	tensDigit
Chapter 5: Repetition
288582	factorial
262070	sumFactors
264885	mortgage
284814	pyramidal
165941	dividesSelf
Chapter 7: Conditional execution
154485	sumDouble
184004	nearHundred
286596	canBeTriangle
172021	close10
Chapter 8: Strings
191914	notString
190570	missingChar
173784	stringE
196441	everyNth
117334	stringSplosion
131516	sameEnds
Chapter 10: More on classes
282350	quadratic