JS achieve DOM node tree traversal

This article will share DOM node tree traversal depth, breadth traversal code.

I just assumed that traverse the body and its structure is as follows:

<body>
    <section class="container">
        <div class="left">
            <div class="menu"></div>
        </div>
        <div class="right">
            <div class="box1"></div>
            <div class="box2"></div>
        </div>
    </section>
</body>

Depth traversal (DFS)

Child child node of all child nodes of the parent node ... been traversed and then traverse its siblings.

输出：[section.container, div.left, div.menu, div.right, div.box1, div.box2]

const DFS = {
    nodes: [],
    do (root) {
        for (let i = 0;i < root.childNodes.length;i++) {
            var node = root.childNodes[i];
            // 过滤 text 节点、script 节点
            if ((node.nodeType != 3) && (node.nodeName != 'SCRIPT')) {
                this.nodes.push(node);
                this.do(node);
            }
        }
        return this.nodes;
    }
}
console.log(DFS.do(document.body));

Breadth traversal (BFS)

All the siblings been traversed parent node re-iterate its child nodes.

输出：[section.container, div.left, div.right, div.menu, div.box1, div.box2]

const BFS = {
    nodes: [],
    do (roots) {
        var children = [];
        for (let i = 0;i < roots.length;i++) {
            var root = roots[i];
            // 过滤 text 节点、script 节点
            if ((root.nodeType != 3) && (root.nodeName != 'SCRIPT')) {
                if (root.childNodes.length) children.push(...root.childNodes);
                this.nodes.push(root);
            }
        }
        if (children.length) {
            var tmp = this.do(children);
        } else {
            return this.nodes;
        }
        return tmp;
    }
}
console.log(BFS.do(document.body.childNodes));

Non-recursive version:

const BFS = {
    nodes: [],
    do (roots) {
        var roots = new Array(...roots);
        for (let i = 0;i < roots.length;i++) {
            var root = roots[i];
            // 过滤 text 节点、script 节点
            if ((root.nodeType != 3) && (root.nodeName != 'SCRIPT')) {
                if (root.childNodes.length) roots.push(...root.childNodes);
                this.nodes.push(root);
            }
        }
        return this.nodes;
    }
}
console.log(BFS.do(document.body.childNodes));

Original: stay small meow love https://www.jianshu.com/p/cef409b161ba

JS achieve DOM node tree traversal

Depth traversal (DFS)

Breadth traversal (BFS)

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