From 6c9d335f05956d05dae5149d70cc03c2198db172 Mon Sep 17 00:00:00 2001
From: Christopher Bohn <bohn@unl.edu>
Date: Wed, 23 Sep 2020 22:15:17 -0500
Subject: [PATCH] Added more switch examples
Shows switching on integers, strings, and enums.
Shows all cases with break, shows intentional fall-through, and shows
idiomatic uncommented fall-through for two identical cases.
---
.../unl/cse/soft160/switches/IfSwitch.java | 2 +
.../cse/soft160/switches/SwitchExamples.java | 90 +++++++++++++++++++
2 files changed, 92 insertions(+)
create mode 100644 src/main/java/edu/unl/cse/soft160/switches/SwitchExamples.java
diff --git a/src/main/java/edu/unl/cse/soft160/switches/IfSwitch.java b/src/main/java/edu/unl/cse/soft160/switches/IfSwitch.java
index b19bda3..e3a90a7 100644
--- a/src/main/java/edu/unl/cse/soft160/switches/IfSwitch.java
+++ b/src/main/java/edu/unl/cse/soft160/switches/IfSwitch.java
@@ -18,6 +18,7 @@ public class IfSwitch {
System.out.println("You entered " + outputString + ".");
}
+ // This version of convertToWord uses a chained conditional
private static String convertToWord(int value) {
String numberText;
if (value == 1) {
@@ -33,6 +34,7 @@ public class IfSwitch {
}
/*
+ // This version of convertToWord uses a switch statement
private static String convertToWord(int value) {
String numberText;
switch (value) {
diff --git a/src/main/java/edu/unl/cse/soft160/switches/SwitchExamples.java b/src/main/java/edu/unl/cse/soft160/switches/SwitchExamples.java
new file mode 100644
index 0000000..11d6364
--- /dev/null
+++ b/src/main/java/edu/unl/cse/soft160/switches/SwitchExamples.java
@@ -0,0 +1,90 @@
+package edu.unl.cse.soft160.switches;
+
+public class SwitchExamples {
+ public enum Temperature {
+ SUMMER, AUTUMN, WINTER, SPRING
+ }
+
+ // This example shows that switch statements can be used with integers
+ // This example also shows the typical situation in which each case ends with break
+ public static String digitToWord(int value) {
+ String numberWord;
+ switch (value) {
+ case 1:
+ numberWord = "one";
+ break;
+ case 2:
+ numberWord = "two";
+ break;
+ case 3:
+ numberWord = "three";
+ break;
+ case 4:
+ numberWord = "four";
+ break;
+ case 5:
+ numberWord = "five";
+ break;
+ case 6:
+ numberWord = "six";
+ break;
+ case 7:
+ numberWord = "seven";
+ break;
+ case 8:
+ numberWord = "eight";
+ break;
+ case 9:
+ numberWord = "nine";
+ break;
+ case 10:
+ numberWord = "ten";
+ break;
+ default: /* The default code should NOT be used for a normal case */
+ numberWord = "an out-of-range value";
+ }
+ return numberWord;
+ }
+
+ // This example shows that switch statements can be used with strings (in Java)
+ // This example also shows that you should add a "fall-through" comment when you intentionally omit a break
+ public static void findVehicleType(String vehicle) {
+ switch (vehicle) {
+ case "Silverado":
+ System.out.println("pickup truck");
+ break;
+ case "Traverse":
+ System.out.println("SUV");
+ break;
+ case "Corvette": /* The "Corvette" case will output "fast car" */
+ System.out.print("fast ");
+ // fall-through
+ case "Cruze":
+ System.out.println("car");
+ break;
+ default:
+ System.out.println("unrecognized vehicle");
+ }
+ }
+
+ // This example shows that switch statements can be used with enumerated types
+ // This example also shows the idiom where it's okay not to add a "fall-through" comment
+ public static String getSeasonalTemperature(Temperature season) {
+ String seasonalTemperature;
+ switch (season) {
+ case SUMMER:
+ seasonalTemperature = "hot";
+ break;
+ case WINTER:
+ seasonalTemperature = "cold";
+ break;
+ case SPRING: /* When two cases are identical, this is the idiom */
+ case AUTUMN:
+ seasonalTemperature = "warm";
+ break;
+ default:
+ seasonalTemperature = "indeterminate";
+ }
+ return seasonalTemperature;
+ }
+}
--
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