如何在 NodeJS 中展开对象数组？

Posted 2023-03-08

【中文标题】如何在 NodeJS 中展开对象数组？

【英文标题】：How to unwind an Array of Objects in NodeJS?

【发布时间】：2016-11-24 15:38:12

【问题描述】：

我想展开一个嵌套了对象数组的对象数组。嵌套层级未定义，且在整个数组中不一致。

这是我的示例数据

var data = [
    id: 1,
    name: 'Harshal',
    subjects: [
        id: 1,
        name: 'English',
        chapters: [
            id: 1,
            name: 'Grammar'
        , 
            id: 2,
            name: 'Comprehension'
        ]
    , 
        id: 2,
        name: 'Maths',
        chapters: [
            id: 1,
            name: 'Algebra'
        , 
            id: 2,
            name: 'Geometry'
        ]
    ]
, 
    id: 2,
    name: 'Pankaj',
    subjects: [
        id: 3,
        name: 'Marathi',
        chapters: [
            id: 1,
            name: 'Kavita',
            topics: [
                id: 1,
                name: 'Topic 1'
            ]
        ]
    , 
        id: 4,
        name: 'Hindi',
        chapters: [
            id: 1,
            name: 'Katha',
            topics: [
                id: 2,
                name: 'Topic 2'
            , 
                id: 3,
                name: 'Topic 3'
            ]
        ]
    ]
];

我想得到这样的输出：

var op = [
    id: 1,
    name: 'Harshal',
    subjects: 
        id: 1,
        name: 'English',
        chapters: 
            id: 1,
            name: 'Grammar'
        
    
, 
    id: 1,
    name: 'Harshal',
    subjects: 
        id: 1,
        name: 'English',
        chapters: 
            id: 2,
            name: 'Comprehension'
        
    
, 
    id: 1,
    name: 'Harshal',
    subjects: 
        id: 2,
        name: 'Maths',
        chapters: 
            id: 1,
            name: 'Algebra'
        
    
, 
    id: 1,
    name: 'Harshal',
    subjects: 
        id: 2,
        name: 'Maths',
        chapters: 
            id: 2,
            name: 'Geometry'
        
    
, 
    id: 2,
    name: 'Pankaj',
    subjects: 
        id: 3,
        name: 'Marathi',
        chapters: 
            id: 1,
            name: 'Kavita',
            topics: 
                id: 1,
                name: 'Topic 1'
            
        
    
, 
    id: 2,
    name: 'Pankaj',
    subjects: 
        id: 4,
        name: 'Hindi',
        chapters: 
            id: 1,
            name: 'Katha',
            topics: 
                id: 2,
                name: 'Topic 2'
            
        
    
, 
    id: 2,
    name: 'Pankaj',
    subjects: 
        id: 4,
        name: 'Hindi',
        chapters: 
            id: 1,
            name: 'Katha',
            topics: 
                id: 3,
                name: 'Topic 3'
            
        
    
];

我曾尝试与pull-unwind 合作，但我想它存在一些问题。如果有人有任何其他想法，我愿意实施。

【参考方案1】：

你试过递归吗？

var data = [
    id: 1,
    name: 'Harshal',
    subjects: [
        id: 1,
        name: 'English',
        chapters: [
            id: 1,
            name: 'Grammar'
        , 
            id: 2,
            name: 'Comprehension'
        ]
    , 
        id: 2,
        name: 'Maths',
        chapters: [
            id: 1,
            name: 'Algebra'
        , 
            id: 2,
            name: 'Geometry'
        ]
    ]
, 
    id: 2,
    name: 'Pankaj',
    subjects: [
        id: 3,
        name: 'Marathi',
        chapters: [
            id: 1,
            name: 'Kavita',
            topics: [
                id: 1,
                name: 'Topic 1'
            ]
        ]
    , 
        id: 4,
        name: 'Hindi',
        chapters: [
            id: 1,
            name: 'Katha',
            topics: [
                id: 2,
                name: 'Topic 2'
            , 
                id: 3,
                name: 'Topic 3'
            ]
        ]
    ]
];

function unravel(obj)

    var out = [];
    var added = false;
    for(var i in obj) 
	if(obj[i] instanceof Array) 
	    for(var j in obj[i]) 
		var r = unravel(obj[i][j]);
		for(var k in r) 
		    var a = ;
		    for(var key in obj)  // make copy of obj
			a[key] = obj[key];
		    
		    a[i] = r[k];
		    added = true;
		    out.push(a);
		
	    
	
    
    if(!added) 
	out.push(obj);
    
    return out;


var op = [];
for(var i in data)
    op = op.concat(unravel(data[i]));
console.log(JSON.stringify(op, null, 4));

【讨论】：

太棒了，这就是我想要的。我曾尝试过递归，但不知何故弄乱了我的逻辑。