in-order traversal

(algorithm)

Definition: Process all nodes of a tree by recursively processing the left subtree, then processing the root, and finally the right subtree.

Generalization (I am a kind of ...)
tree traversal, depth-first search.

Aggregate parent (I am a part of or used in ...)
treesort (1).

Note: For instance, if the "processing" is just printing, a tree is printed as "(left subtree) root (right subtree)." Here is pseudocode for a binary tree:

 inorder(tree)
 begin
     if tree is null, return;

     inorder(tree.left_subtree);
     print(tree.root);
     inorder(tree.right_subtree);
 end

Author: PEB

More information

animation (Java)

Go to the Dictionary of Algorithms and Data Structures home page.

If you have suggestions, corrections, or comments, please get in touch with Paul Black.

Entry modified 14 August 2008.
HTML page formatted Mon Feb 2 13:10:39 2015.

Cite this as:
Paul E. Black, "in-order traversal", in Dictionary of Algorithms and Data Structures [online], Vreda Pieterse and Paul E. Black, eds. 14 August 2008. (accessed TODAY) Available from: http://www.nist.gov/dads/HTML/inorderTraversal.html