Difference between revisions of "CISC181 F2017 Lab1"
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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   | + | * 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>.  | 
| − | * Whatever value is returned by   | + | * Whatever value is returned by <tt>countOccurrences()</tt>,   | 
* If a valid choice is made, call the corresponding function immediately.  Otherwise print an error message  | * If a valid choice is made, call the corresponding function immediately.  Otherwise print an error message  | ||
* Let the program end (no loop -- just print prompt, read response, and execute ''one'' time)  | * Let the program end (no loop -- just print prompt, read response, and execute ''one'' time)  | ||
| Line 17: | Line 17: | ||
===<tt>static int countOccurrences(char c, String S)</tt>===  | ===<tt>static int countOccurrences(char c, String S)</tt>===  | ||
| − | Iterate through every character in the String S and count how many   | + | Iterate through every character in the String S and count how many times char c occurs.  Return this value.  | 
| − | ===<tt>static void drawLayeredPyramid(int numLayers)</tt>===  | + | ===<tt>static void drawLayeredPyramid(int numLayers, char firstChar, char secondChar)</tt>===  | 
| − | + | 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.  | ||
| + | <tt>drawLayeredPyramid()</tt> should make a similar pattern with <tt>numRows</tt> rows, alternating characters <tt>firstChar</tt> and <tt>secondChar</tt>.  | ||
Revision as of 21:45, 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 single character and a string, each on separate lines. Read these with a Scanner object and pass them to countOccurrences().
 - Whatever value is returned by countOccurrences(),
 - If a valid choice is made, call the corresponding function immediately. Otherwise print an error message
 - Let the program end (no loop -- just print prompt, read response, and execute one time)
 
static int countOccurrences(char c, String S)
Iterate through every character in the String S and count how many times char c 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.