# Binary Tree Level Order traversal in java

Table of Contents

If you want to practice data structure and algorithm programs, you can go through 100+ java coding interview questions.

This is 5th part of java binary tree tutorial.

In this post, we will see about Level Order binary tree traversal in java.

## Level Order traversal

Level order traversal of below binary tree will be:

We will use Queue for Level Order traversal.This algorithm is very similar to Breadth first search of graph.
Steps for Level order traversal algorithm:

1. Create empty `queue` and pust `root` node to it.
2. Do the following when `queue` is not empty
• `Pop` a node from `queue` and print it
• `Push left child` of popped node to `queue` if not null
• `Push right child` of popped node to `queue` if not null
Example:
Lets say your binary tree is :

So Level Order traversal will work as below:

Lets create java program for level order traversal:

Run above program and you will get following output:

Level Order traversal of binary tree will be:
40 20 60 10 30 50 70

## Java Binary tree tutorial

Please go through java interview programs for more such programs.

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## Comments

1. Juan C. says:

You have a typo after explain how Level Order traversal works on “Lets create java program for PreOrder traversal:” it is not PreOrder, anyway everything is well explained and is easy to see that is a typo.

2. Saket Kumar says:

Really good explanation

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