I'm wrapping up the first part of the Helsinki Uni MOOC full stack course, and I've just finished the section on conditionals. I understand there's memory allocation that happens under the hood, and I'm curious whether my example code (albeit a simplified version) would benefit from using 2 or 3 conditionals, or if the single conditional I've written is sufficient for runtime and memory efficiency. Does it really make a difference, or are we just overthinking it? Here's my code:
```java
import java.util.Scanner;
public class LeapYear {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.print("Give a year:");
int year = Integer.valueOf(scan.nextLine());
if ((year % 4 == 0 && year % 100 != 0) || (year % 100 == 0 && year % 400 == 0)) {
System.out.println("The year is a leap year.");
} else {
System.out.println("The year is not a leap year");
}
}
}
```
4 Answers
If you manage to save any memory, it might only be a handful of bytes, which is insignificant. With costs of memory dropping so low, the real value lies in programmer time, which is way more expensive. Always prioritize readability over micro-optimizations.
When it comes to runtime and memory usage, the performance impact from these slight 'optimizations' is negligible these days. Instead of stressing over that, focus on readability, organizing your project, and using sensible data structures. That's where your energy is best spent.
Honestly, it probably doesn't make a difference. Once the Just-In-Time (JIT) compiler has optimized your code, they might turn out to be the same in performance.
Personally, I’d structure it with a series of checks that can each return a result. If you test many random years, your code could immediately respond false for about 75% of them with just one check. Here’s a way to rewrite it:
```java
public static boolean isLeapYear(int year) {
if (year % 4 != 0) {
return false;
}
if (year % 400 == 0) {
return true;
}
if (year % 100 == 0) {
return false;
}
return true;
}
```
This way, you can avoid nesting and keep it clean!
I agree with you! I try to flatten the conditionals too, just like in your second example. I read somewhere that having multiple return statements is considered an anti-pattern, but I find your second snippet much easier to understand than the first one.
Haha, I had to look up 'JIT' too! Thanks for the clarification!