首先定義二叉樹的結構:

// 定義二叉樹的結構
function Tree(left, label, right) {this.left = left;this.label = label;this.right = right;
}// 對二叉樹采用中序遍歷
function* inorder(t) {if(t) {yield* inorder(t.left);yield t.label;yield* inorder(t.right);}
}// 生成二叉樹
function make(array) {if (array.length === 1) return new Tree(null, array[0], null);return new Tree(make(array[0]), array[1], make(array[2]));
}let tree = make([['a'], 'b', ['c']], 'd', [['e'], 'f', ['g']]]);// 遍歷二叉樹
var result = [];
for (let node of inorder(tree)) {result.push(node);
}
console.log(result);

參考《ES6標準入門》(第3版)P341