Java devs, get the rope!

good-example.hs

-- Algebraic data type definition
data Tree a = Empty | Node (Tree a) a (Tree a) deriving (Show)

-- Insertion function
insert :: (Ord a) => a -> Tree a -> Tree a
insert x Empty = Node Empty x Empty
insert x (Node left v right)
    | x < v     = Node (insert x left) v right
    | otherwise = Node left v (insert x right)

-- Search function
search :: (Ord a) => a -> Tree a -> Bool
search _ Empty = False
search x (Node left v right)
    | x == v    = True
    | x < v     = search x left
    | otherwise = search x right
   
--- #############################################
let tree = foldr insert Empty [5,3,7,9,1]
search 7 tree  -- True

shitty-example.java

// Java class-based binary tree implementation
class TreeNode<T extends Comparable<T>> {
    T value;
    TreeNode<T> left;
    TreeNode<T> right;

    TreeNode(T value) {
        this.value = value;
        this.left = null;
        this.right = null;
    }

    void insert(T newValue) {
        if (newValue.compareTo(value) < 0) {
            if (left == null) left = new TreeNode<>(newValue);
            else left.insert(newValue);
        } else {
            if (right == null) right = new TreeNode<>(newValue);
            else right.insert(newValue);
        }
    }

    boolean search(T target) {
        if (value.equals(target)) return true;
        else if (target.compareTo(value) < 0) return left != null && left.search(target);
        else return right != null && right.search(target);
    }
}

// #################################################

TreeNode<Integer> root = new TreeNode<>(5);
root.insert(3);
root.insert(7);
boolean found = root.search(7); // true