# Replace Multi Branch If By Switch
# Description
In Java 14, switch expressions (opens new window) turned into a standard feature. This rule replaces multi-branch if statements by corresponding switch expressions or switch statements with switch labeled rules. Because this rule removes a lot of redundant parts of code, readability is improved.
Requirements
- Java 14
# Benefits
Removes code clutter. Improves readability.
# Tags
# Code Changes
# Initializing a Variable
Pre
String weekDayName;
if (weekDay == 1) {
weekDayName = "Monday";
} else if (weekDay == 2) {
weekDayName = "Tuesday";
} else if (weekDay == 3) {
weekDayName = "Wednesday";
} else if (weekDay == 4) {
weekDayName = "Thursday";
} else if (weekDay == 5) {
weekDayName = "Friday";
} else if (weekDay == 6) {
weekDayName = "Saturday";
} else if (weekDay == 7) {
weekDayName = "Sunday";
} else {
weekDayName = "";
}
Post
String weekDayName = switch (weekDay) {
case 1 -> "Monday";
case 2 -> "Tuesday";
case 3 -> "Wednesday";
case 4 -> "Thursday";
case 5 -> "Friday";
case 6 -> "Saturday";
case 7 -> "Sunday";
default -> "";
};
# Computing a Returned Value
Pre
String getWeekDayName(int weekDay) {
if (weekDay == 1) {
return "Monday";
} else if (weekDay == 2) {
return "Tuesday";
} else if (weekDay == 3) {
return "Wednesday";
} else if (weekDay == 4) {
return "Thursday";
} else if (weekDay == 5) {
return "Friday";
} else if (weekDay == 6) {
return "Saturday";
} else if (weekDay == 7) {
return "Sunday";
} else {
return "";
}
}
Post
String getWeekDayName(int weekDay) {
return switch (weekDay) {
case 1 -> "Monday";
case 2 -> "Tuesday";
case 3 -> "Wednesday";
case 4 -> "Thursday";
case 5 -> "Friday";
case 6 -> "Saturday";
case 7 -> "Sunday";
default -> "";
};
}
# Switch Expression with Throw Statement
Pre
String getWeekDayName(int weekDay) {
if (weekDay == 1) {
return "Monday";
} else if (weekDay == 2) {
return "Tuesday";
} else if (weekDay == 3) {
return "Wednesday";
} else if (weekDay == 4) {
return "Thursday";
} else if (weekDay == 5) {
return "Friday";
} else if (weekDay == 6) {
return "Saturday";
} else if (weekDay == 7) {
return "Sunday";
} else {
throw new IllegalArgumentException("Invalid number for weekday");
}
}
Post
String getWeekDayName(int weekDay) {
return switch (weekDay) {
case 1 -> "Monday";
case 2 -> "Tuesday";
case 3 -> "Wednesday";
case 4 -> "Thursday";
case 5 -> "Friday";
case 6 -> "Saturday";
case 7 -> "Sunday";
default -> throw new IllegalArgumentException("Invalid number for weekday");
};
}
# Combining Cases
Pre
String getTitle(int weekDay) {
if (weekDay == 1 || weekDay == 3 || weekDay == 5) {
return "Timetable For Monday, Wednesday, Friday";
} else if (weekDay == 2 || weekDay == 4 || weekDay == 6) {
return "Timetable For Tuesday, Thursday, Saturday";
} else {
return "Timetable For Sunday Or Holiday";
}
}
Post
String getTitle(int weekDay) {
return switch (weekDay) {
case 1, 3, 5 -> "Timetable For Monday, Wednesday, Friday";
case 2, 4, 6 -> "Timetable For Tuesday, Thursday, Saturday";
default -> "Timetable For Sunday Or Holiday";
};
}
# Switch Statement with Switch Labeled Rules
Pre
if (weekDay == 1 || weekDay == 3 || weekDay == 5) {
setTitle("Timetable For Monday, Wednesday, Friday");
} else if (weekDay == 2 || weekDay == 4 || weekDay == 6) {
setTitle("Timetable For Tuesday, Thursday, Saturday");
} else {
setTitle("Timetable For Sunday Or Holiday");
}
Post
switch (weekDay) {
case 1, 3, 5 -> setTitle("Timetable For Monday, Wednesday, Friday");
case 2, 4, 6 -> setTitle("Timetable For Tuesday, Thursday, Saturday");
default -> setTitle("Timetable For Sunday Or Holiday");
}
🛠️ Auto-refactor Available
You can auto refactor this with jSparrow.
Drop this button to your Eclipse IDE workspace to install jSparrow for free:
Need help? Check out our installation guide.
# Properties
| Property | Value |
|---|---|
| Rule ID | ReplaceMultiBranchIfBySwitch |
| First seen in jSparrow version | 4.13.0 |
| Minimum Java version | 14 |
| Remediation cost | 15 min |