breathTraversal.js

function breathTraversal(tree) {

  var queue = [tree];

  var result = [];

  while (queue.length > 0) {

    var node = queue.shift();
    result.push(node.value);

    node.left && queue.push(node.left);
    node.right && queue.push(node.right);
  }
  console.log('result of breath traversal :', result);
}
breathTraversal(tree);