深拷贝
function clone(source) { var target = {}; for(var i in source) { if (source.hasOwnProperty(i)) { if (typeof source[i] === 'object') { target[i] = clone(source[i]); // 注意这里 } else { target[i] = source[i]; } } } return target; }
function createData(deep, breadth) { var data = {}; var temp = data; for (var i = 0; i < deep; i++) { temp = temp['data'] = {}; for (var j = 0; j < breadth; j++) { temp[j] = j; } } return data; } createData(1, 3); // 1层深度,每层有3个数据 {data: {0: 0, 1: 1, 2: 2}} createData(3, 0); // 3层深度,每层有0个数据 {data: {data: {data: {}}}}
用循环遍历一棵树,需要借助一个栈,当栈为空时就遍历完了,栈里面存储下一个需要拷贝的节点
首先我们往栈里放入种子数据,key
用来存储放哪一个父元素的那一个子元素拷贝对象
然后遍历当前节点下的子元素,如果是对象就放到栈里,否则直接拷贝
function cloneLoop(x) { const root = {}; // 栈 const loopList = [ { parent: root, key: undefined, data: x, } ]; while(loopList.length) { // 深度优先 const node = loopList.pop(); const parent = node.parent; const key = node.key; const data = node.data; // 初始化赋值目标,key为undefined则拷贝到父元素,否则拷贝到子元素 let res = parent; if (typeof key !== 'undefined') { res = parent[key] = {}; } for(let k in data) { if (data.hasOwnProperty(k)) { if (typeof data[k] === 'object') { // 下一次循环 loopList.push({ parent: res, key: k, data: data[k], }); } else { res[k] = data[k]; } } } } return root; }