Why does the compiler not complain in this case?

Question

this is the code:

 private TreeNode GetTopLevelNode(TreeNode childNode)
    {
        if (childNode == null)
            throw new ArgumentNullException("childNode", "childNode is null.");

        if (childNode.Parent == null) return childNode;

        TreeNode node = childNode;
        while (true)
        {
            if (node.Parent == null)
            {
                return node;
            }
            node = node.Parent;
        }

    }

in a while loop, only if node.Parent == null returns node,

why does the compiler not report the error "not all path codes return a value"?

if 'node.Parent == null' cannot be satisfied, then the node tree will not be returned. The compiler cannot detect this situation?

Answer 1

Since you are using while(true){, there is no other way to exit the loop than using return. if node.parent == nullit cannot be done, then it will be an infinite loop. Thus, it is impossible to go past the loop without returning, and the compiler does not complain.

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