Changes between Initial Version and Version 1 of ControlSystems/SoftwareTeam/Training/GettingStarted/Loops

Timestamp:

Nov 4, 2019, 3:37:07 PM (6 years ago)

Author:

David Albert

Comment:

--

ControlSystems/SoftwareTeam/Training/GettingStarted/Loops

@@ +1 @@
+It's important for a program to be able to do things repeatedly; for example, a robot must read its sensors repeatedly and react only when certain conditions are met.  
+
+1. Create a new project folder named !LoopExample
+1. Open the !LoopExample folder
+1. Create a new file (File->New File)
+1. Cut and paste the following program into the editor:
+{{{
+public class LoopExample {
+    public static void main(String args[]) {
+        int counter;  
+
+        counter = 1;
+        while (counter <= 10) {
+            System.out.println(counter);
+            counter = counter + 1;
+        }
+    }
+}
+}}}
+1. Save the program as !LoopExample.java
+1. Run the program in the debugger with a breakpoint set at the line while (counter <= 10)
+1. Step through the program a line at a time, observing the program output, variables, and flow of execution
+
+=== Understanding the program
+Our program:
+1. Creates a loop counter variable
+1. Initializes the loop counter to 1
+1. Repeatedly evaluates the expression (counter <= 10) and while the expression evaluates as true
+   1. prints the counter value
+   1. increments the counter value by 1
+
+The result of running the program is that the numbers 1 through 10 are printed.
+With only 10 iterations of the loop, you might ask whether it might be easier to just print each number manually,
+but consider a loop that might require thousands of iterations or that might run indefinitely until something happened:
+{{{
+    while (distanceToTarget > 0) {
+       driveForward(0.50);
+       distanceToTarget = checkDistance();
+    }
+}}}
+
+Java includes three types of loop statements: 
+   * while
+   * for
+   * do
+
+=== Extra credit
+* Read more about [https://www.geeksforgeeks.org/loops-in-java/ Java loops] 
+* Re-write the sample program using a '''do''' loop
+* Re-write the sample program using a '''for''' loop