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.