Difference between revisions of "CISC181 F2017 Lab1"

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(static int countOccurrences(char searchChar, String S))
(static void main(String[] args))
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Your <tt>main()</tt> should do the following:
 
Your <tt>main()</tt> should do the following:
  
* Ask the user (using <tt>println()</tt> or <tt>printf()</tt>) to input a single character and a string, each on separate lines.  Read these with a <tt>Scanner</tt> object and pass them to <tt>countOccurrences()</tt>.
+
* Ask the user (using <tt>println()</tt> or <tt>printf()</tt>) to input a string on its own line.  Read this with a <tt>Scanner</tt> object and pass it to <tt>mostCommonChar()</tt>.
* Whatever value is returned by <tt>countOccurrences()</tt>,
+
* Ask the user to enter two chars and a positive, even number.  Read these with your <tt>Scanner</tt> object and pass them to <tt>drawInvertedPyramid</tt>.
* If a valid choice is made, call the corresponding function immediately.  Otherwise print an error message
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* For all user inputs, check for legality here in <tt>main()</tt>If there is a problem, print an informative error message and let the program end.
* Let the program end (no loop -- just print prompt, read response, and execute ''one'' time)
 
  
 
===<tt>static int countOccurrences(char searchChar, String searchString)</tt>===
 
===<tt>static int countOccurrences(char searchChar, String searchString)</tt>===

Revision as of 21:55, 11 September 2017

  • Make a new project (but now n = 1) following these instructions
  • Name your class "Lab1". This happens when you are creating a new module, in the Java class name field
    • Add your name and section number in a comment before the class declaration
    • As explained in the subsections below, modify static void main() and create two other methods: static void countOccurrences() { ... } and static void printLayeredPyramid() { ... }
  • Submit your Lab1.java on Sakai by Monday, September 18

static void main(String[] args)

Your main() should do the following:

  • Ask the user (using println() or printf()) to input a string on its own line. Read this with a Scanner object and pass it to mostCommonChar().
  • Ask the user to enter two chars and a positive, even number. Read these with your Scanner object and pass them to drawInvertedPyramid.
  • For all user inputs, check for legality here in main(). If there is a problem, print an informative error message and let the program end.

static int countOccurrences(char searchChar, String searchString)

Iterate through every character in the String searchString and count how many times char searchChar occurs. Return this value.

static void drawLayeredPyramid(int numLayers, char firstChar, char secondChar)

Consider the following pattern:

$$$$$$$$$$
 ¢¢¢¢¢¢¢¢¢
  $$$$$$$$
   ¢¢¢¢¢¢¢
    $$$$$$
     ¢¢¢¢¢
      $$$$
       ¢¢¢
        $$
         ¢

It consists of 10 alternating rows of $ and ¢ characters. The first row has 10 columns of characters, and each successive row has one less. drawLayeredPyramid() should make a similar pattern with numRows rows, alternating characters firstChar and secondChar.