js将多维数组格式化展开成树状结构

js将多维数组格式化展开成树状结构

用js实现将二维数组格式化转换成树状结构。

eg:待转数组：

var array1 = [
    ["a", "aa", "aaa", "aaaa"],
    ["b", "bb", "bbb"],
    ["a", "ab", "aba"],
    ["a", "aa", "aab"]
]

目标数组：

[{
    "name" : "a",
    "child" : [
        {
            "name" : "aa",
            "child" : [
                {
                    "name" : "aaa",
                    "child" : [
                        {
                            "name" : "aaaa",
                            "child" : []
                        }
                    ]
                },
                {
                    "name" : "aab",
                    "child" : []
                }
            ]
        },
        {
            "name" : "ab",
            "child" : [
                {
                    "name": "aba",
                    "child" : []
                }
            ]
        }
    ]
},
{
    "name": "b",
    "child" : [
        {
            "name" : "bb",
            "child" : [
                {
                    "name" : "bbb",
                    "child" : []
                }
            ]
        }
    ]
}]

上代码：

function toTree(arr) {
	const obj = {};
	const res = [];
	for (let i = 0; i < arr.length; i++) {
	    for (let j = 0; j < arr[i].length; j++) {
	        const item = arr[i][j];
	        if (!obj[item]) {
	            obj[item] = {
	                name: item,
	                child: [],
	            };
	        }
	        if (j > 0) {
	            const parent = obj[arr[i][j - 1]];
	            if (parent) {
	                if (parent.child.indexOf(obj[item]) < 0) {
	                    parent.child.push(obj[item]);
	                }
	            }
	        } else {
	            if (res.indexOf(obj[item]) < 0) {
	                res.push(obj[item]);
	            }
	        }
	    }
	}
	return res;
}