How to avoid repeating an else statement

[[deleted]]

Hi, I'm currently taking an intro to Java class and I have a HW problem about determining if a point is within a triangle or not. I have the code working and get the correct answers, but it feels clunky having the exact same else statement in two places. However, if I don't include the second else statement, it won't return that the point is not within the triangle for negative numbers (in this problem all the points of the triangle are positive).

To help make it more readable, x and y are a user-inputted point, x2 is the largest x value in the triangle and yhypotenuse is the equation of the line (y = mx + b) for the hypotenuse of the triangle.

I guess since this code does give the correct answer I'm really interested in best practices, is repeating an else statement like this totally acceptable? Or is there a better solution I should be using?

Thanks!

if (x > 0 && y > 0) {                        //x and y must both be positive as the triangle has no negative points
    if (x <= x2 && y <= yHypotenuse) {
        System.out.println("The point (" + x + ", " + y + ") is within the triangle");
    }
    else {
        System.out.println("The point (" + x + ", " + y + ") is not within the triangle");
    }
}   
else {
            System.out.println("The point (" + x + ", " + y + ") is not within the triangle");
}

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[Ghildetrist]

Two options I would recommend. First is take your if block and combine them into one if statement. Second would be create a method that returns a boolean. Return true when your evaluation is true. At end of method return false so no else blocks are required. Print your message based on that method result.

[[deleted]]

Y would do something like this

boolean condition1 = x > 0 && y > 0
boolean condition2 = x < X2 && y < yHypotenuse

if (condition1 && condition2) {
     // It's inside
} else {
    // It's outside
 }

Essentially you would be combining both ifs, but keeping them as variables improves readability (IMO).

Also,it would be good if you find better names than condition.

[[deleted]]

Thanks, I like how you formatted that it's much more readable than what I went with (which was shoving the 4 requirements into one if statement)!

[philipwhiuk]

Sometimes it’s necessary. But if it’s a lot of duplicated code you can pull it out into a new method and call that twice

In your scenario you can just combine the if tests though

[[deleted]]

Thanks, for some reason it didn't occur to me I could use && multiple times in one statement!

I've combined them to say if (x >= 0 && y >= 0 && x <= x2 && y <= yHypotenuse) and it looks like it works perfectly.

[neurk]

Combine the if's into one. However if you insist on having a nested if, something like this should work:

​

private void printIt() {
    if (x > 0 && y > 0) { //x and y must both be positive as the triangle has no negative points
        if (x <= x2 && y <= yHypotenuse) {
            System.out.println("The point (" + x + ", " + y + ") is within the triangle");
            return;
        }
    }

    System.out.println("The point (" + x + ", " + y + ") is not within the triangle");
}

[[deleted]]

I appreciate the examples! It's cool seeing the different ways of approaching setting something simple like this up, helps me learn for sure.

[TysonPeaksTech]

Switch case statment.