Conditional statements are essential in programming, it gives us the power to control how our code runs depending on certain conditions. In Java, the if statement is a basic building block for setting up conditions in our code. When working with if-else statements that have lots of conditions, it’s crucial to enhance the way we write the code so that it’s easy to read and maintain. In this article, we’ll explore several techniques to refine our syntax, accompanied by examples for a better understanding.
1. Importance of Clear and Efficient Code
- Readability and Human Understanding: Simple and understandable code helps developers, especially when dealing with complicated logical conditions. It makes it easier for the programmer to understand the logic and purpose behind the code, reducing the mental effort required.
- Maintainability / Ease of Modification: Easy-to-understand code is easier to take care of. When you need to make changes, developers can quickly get what the code is doing and make adjustments without making mistakes. This is important for projects that last a long time and involve teamwork.
- Simplifies Troubleshooting: Simple and clear code helps in finding and fixing problems. When there are issues, developers can quickly figure out what’s going wrong and solve it faster, saving time on fixing things.
- Reduced Error Rate and Minimizes Mistakes: Easy-to-read and well-organized code lowers the chance of making mistakes when creating or changing things. Developers are less likely to misunderstand the logic or make errors in the code’s structure.
- Team Collaboration: In a collaborative environment, different developers might be working on the same code. Clear code makes sure that team members can grasp what others have done, promoting collaboration and making it simpler for everyone to add to or check the code.
- Easier to Scale: As projects get bigger, easy-to-understand code becomes more important. It makes it simpler to add new features or make changes, helping the software to grow smoothly.
- Facilitates Code Reviews: Easy-to-understand code is crucial for good code reviews. When checking the code, team members can easily judge if the logic is right and if the coding rules are followed, leading to better overall code quality.
- Facilitates Performance Tuning: Good code is important for making things run well. When
if-elsestatements are clear and efficient, developers can work on making things run better without getting stuck in complicated logic.
2. Problem Statement
Let’s consider a scenario where we want to check if a variable number is less than 5, greater than 10, or even. Below is an example illustrating the challenge:
public class MultipleOrConditionsExample {
public static void main(String[] args) {
int number = 7;
if (number < 5) {
if (number > 10) {
if (number % 2 == 0) {
System.out.println("The number satisfies one of the conditions.");
}
}
}
System.out.println("The number does not satisfy any of the conditions.");
}
}
When we run the above code, we get the following output as shown in Fig 1.0
The problem includes addressing issues related to code readability, potential logical errors, and the overall maintainability of the codebase. The challenge is to come up with a solution that keeps the code easy to read and clear even when there are more conditions. This ensures that the code stays manageable and free of mistakes.
Let’s implement the above if-else statements with multiple conditions to improve readability and clarity. The above code becomes:
public class MultipleConditions {
public static void main(String[] args) {
int number = 7;
// The following if statement has multiple 'or' conditions
if (number < 5 || number > 10 || number % 2 == 0) {
System.out.println("The number satisfies one of the conditions.");
} else {
System.out.println("The number does not satisfy any of the conditions.");
}
}
}
If we run the above code, we will get the same output shown in Fig 1.0.
3. Best Practices for Formatting Multiple Conditions in If-Else Statements
To enhance the readability, maintainability, and robustness of code with multiple conditions in an if statement, consider the following approaches:
3.1 Indentation and Braces
Maintain uniform and correct indentation. Use braces {} for the if and else blocks, even if they contain only a single statement. This maintains a consistent coding style and stops mistakes from happening.
3.1.1 Example Code
if (condition1 || condition2 || condition3) {
// Code block for the first condition
} else if (condition4 && condition5) {
// Code block for the second condition
} else {
// Default code block if none of the conditions is met
}
3.2 Use Parentheses to Clarify Logic
When combining multiple conditions, always use parentheses to explicitly define the order of evaluation. This not only ensures that the conditions are checked in the intended sequence but also improves code readability. Without parentheses, the default operator precedence might lead to unexpected results.
3.2.1 Example Code
// Unclear without parentheses
if (number < 5 || number > 10 || number % 2 == 0) {
// Code block
}
// Clear with parentheses
if ((number < 5 || number > 10) || (number % 2 == 0)) {
// Code block
}
3.3 Avoid Nested If-Else Statements
Nested if-else statements can quickly become complex and difficult to comprehend. Instead, think about refactoring your code to make it simpler and use logical operators to combine conditions in a smart way. This makes your code easier to read and lowers the chance of introducing mistakes.
3.3.1 Example Code
// Nested if-else
if (number > 10) {
if (number % 2 == 0) {
// Code block
}
} else {
// Code block
}
}
// Flattened if-else
if ((number > 10) || (number % 2 == 0)) {
System.out.println("The number satisfies one of the conditions.");
} else {
System.out.println("The number does not satisfy any of the conditions.");
}
3.4 Use Descriptive Variable Names
Assign meaningful names to variables representing conditions. This makes the code self-explanatory, reducing the need for comments to explain the logic. Developers reading your code can quickly grasp the purpose of each condition.
3.4.1 Example Code
int number = 7;
// Less descriptive
if (number > 10 || number < 5 || number % 2 == 0) {
// Code block
}
// More descriptive
boolean isOutOfRange = (number < 5 || number > 10);
boolean isEven = (number % 2 == 0);
if (isOutOfRange || isEven) {
System.out.println("The number satisfies one of the conditions.");
} else {
System.out.println("The number does not satisfy any of the conditions.");
}
3.5 Extract Conditions to Methods
If conditions become complex, consider extracting them into separate methods. This improves readability and allows for code reuse.
3.5.1 Example Code
int number = 7;
if (isOutOfRange(number) || isEven(number)) {
System.out.println("The number satisfies one of the conditions.");
} else {
System.out.println("The number does not satisfy any of the conditions.");
}
// Method definitions
private static boolean isOutOfRange(int number) {
return number < 5 || number > 10;
}
private static boolean isEven(int number) {
return number % 2 == 0;
}
3.6 Use Ternary Operator for Simplicity
For straightforward conditions, if-else statements can be replaced with the ternary operator for more concise code. However, be careful when using this method so that you don’t compromise how easy it is to read.
3.6.1 Example Code
// If-else statement
int number = 7;
if (number < 5) {
// code block
}
if (number > 10) {
//code block
} else {
// code block
}
// Ternary operator
String result = (number < 5 || number > 10 || number % 2 == 0) ? "Satisfies" : "Does not satisfy";
System.out.println("The number " + result + " the conditions.");
3.7 Utilize Switch Statements for Multiple Values
When dealing with multiple values for a single variable, consider using a switch statement instead of a long chain of if-else statements. Using switch statements makes the code easier to read, and the compiler can make it run faster.
3.7.1 Example Code
// If-else chain
if (day == 1) {
// Code block
} else if (day == 2) {
// Code block
} else if (day == 3) {
// Code block
}
// ...and so on
// Switch statement
switch (day) {
case 1:
// Code block
break;
case 2:
// Code block
break;
case 3:
// Code block
break;
// ...and so on
}
3.8 Consider Enumerations for Readability
If you have specific values to deal with, think about using enums. They make it easy to show and compare values, which makes your code easier to manage.
3.8.1 Example Code
enum Season {
SPRING, SUMMER, AUTUMN, WINTER
}
Season currentSeason = Season.SUMMER;
if (currentSeason == Season.SUMMER || currentSeason == Season.AUTUMN) {
// Code block
}
4. Conclusion
Crafting clear and efficient if-else statements with multiple conditions is a skill that enhances code readability and maintainability. By understanding the logic flow, using parentheses to clarify conditions, avoiding nested structures, employing descriptive variable names, and considering alternative constructs like switch statements and enums, you can create code that is both expressive and easy to comprehend.
5. Download the Source Code
This was a tutorial on Writing Clear and Efficient If-Else Statements with Multiple ‘or’ Conditions in Java.
You can download the full source code of this example here: Java multiple or conditions in if statement.
