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This lab is dedicated to practicing Java fundamentals. These problems will challenge your understanding of Java's built-in primitive values (ints, floats, doubles, Strings, booleans), for loops, while loops, if statements, functions, parameters and return statements.

Create a file for each challenge. Each file should have a main method. Our solution has these four files:

• Pluralize.java
• FlipNCoins.java
• CommandLineClock.java
• SpeedCheck.java

Here's an example Java program with examples of Java syntax.

public class Main {
  public static void main(String[] args) {
    String greeting = "Welcome to my Java program.";
    System.out.println(greeting);
    
    int x = 7;
    float f = 42.3;
    double d = 42.3;
    
    // execute the function called "loopTo" and pass 10 as a parameter
    loopTo(10);
    
    int four = 4;
    int result = double(four);
    System.out.println(four + " doubled is " + result);
  }
  
  // Functions that return nothing have a return type of "void"
  public void loopTo(int max) {
    for (int i = 0; i < max; i++) {
      System.out.println("Loop #" + i);
    }
  }
  
  // This function has a return type of "int"
  public int double(int n) {
    return n * 2;
  }
}

Write a function called pluralize that accepts a word and a number and returns a string with the word pluralized with an "s" if the number is zero, or greater than one.

int dogCount = 1;
System.out.println("I own " + dogCount + " " + pluralize("dog", dogCount) + ".");

int catCount = 2;
System.out.println("I own " + catCount + " " + pluralize("cat", catCount) + ".");

int turtleCount = 0;
System.out.println("I own " + turtleCount + " " + pluralize("turtle", turtleCount) + ".");

I own 1 dog.
I own 2 cats.
I own 0 turtles.

Write a function called flipNHeads that accepts an integer n and flips coins until n heads are flipped in a row. Simulate coin flipping by choosing a random number between 0 and 1. Numbers below .5 are considered tails. Numbers equal and above .5 are considered heads. Print out heads or tails on one line for each flip. Print It took FLIPS flips to flip N heads in a row. once n heads have been in a row.

flipNHeads(1)

Example output:

tails
tails
tails
heads
It took 4 flips to flip 1 head in a row.

heads
It took 1 flip to flip 1 head in a row.

tails
heads
tails
tails
heads
heads
It took 6 flips to flip 2 heads in a row.

Write a program that uses Java's built-in LocalDateTime object to constantly print out the current time to the console, second by second. The program should run until someone manually kills it with CTRL-C or presses the "stop" button in their IDE. Each time should only be printed once. Your program should detect when the seconds increase and only print something out when the timestamp changes.

Zero-pad single digit numbers as strings so 9 shows up as 09 so the timestamp is always the same number of characters.

12:10:58
12:10:59
12:11:00
12:11:01
12:11:02
12:11:03

You can create a LocalDateTime object and get the hours, minutes and seconds off it like this:

LocalDateTime now = LocalDateTime.now();
int hour = now.getHour();
int minute = now.getMinute();
int second = now.getSecond();

Write comments

Upgrade the command line clock to show how fast the program is processing itself between time updates. Display the speed in hertz, kilohertz, megahertz, or gigahertz (Hz, kHz, MHz, GHz). A hertz is defined as "one cycle per second." A computer that executes one operation per second is a 1 Hz computer.

• Hz - 1 cycle per second
• kHz - 1,000 cycles per second
• MHz - 1,000,000 cycles per second
• GHz - 1,000,000,000 cycles per second

Note: Java won't allow you to write commas in large numbers. Use underscores instead.

// commas won't compile
// int million = 1,000,000;
// underscores compile
int million = 1_000_000;

Count how many times the while loop executes between displaying each second and show how many Hertz your program is operating at.

11:43:57 4.774371 MHz
11:43:58 4.747498 MHz
11:43:59 4.796893 MHz
11:44:00 3.900095 MHz
11:44:01 4.513468 MHz
11:44:02 4.462237 MHz
11:44:03 4.536814 MHz
11:44:04 4.791471 MHz

The speed you're seeing in the program shouldn't necessary be the speed you see printed on your computer. The program isn't running raw on your CPU. It also takes time to read the system time, peel off the second value, and compare it to the previous value so there's really more than just "one" operation happening here.

• Work in a fork of this repository
• Work in a branch on your fork
• Write all of your code in a directory named lab- + <your name> e.g. lab-susan
• Open a pull request to this repository
• Submit on canvas a question and observation, how long you spent, and a link to your pull request