如何遍历对象的嵌套子代并收集名称数组

Question

There is n number of parent and child in an object

var obj={
    name:'one',
    child:{
        name:'two',
        child:{
            name:'three',
            child..
        }
    }
} 

foo(obj)                        

Write a function to get output as ['one', 'two, 'three', ...]

Answer 1

you should use a recursive function

var result = [];

function searchChildren(parent){
    if(parent.child){
        result.push(parent.name);
        searchChildren(parent.child);
    }
}

searchChildren(obj);

https://jsfiddle.net/zrbfm9ud/

Answer 2

This is one way to do it, basically you return and have function call itself again. Kinda like a loop.

var obj={
    name:'one',
    child:{
        name:'two',
        child:{
            name:'three'
        }
    }
} 


function foo(obj, arr) {
  if (!obj) return arr;
  arr.push(obj.name);
  return foo(obj.child, arr);
}

var results = foo(obj,[]);

Answer 3

Use a while loop to iterate through each level of your object until object.child cannot be found:

 function foo(object) { var result = [] while (object) { result.push(object.name) object = object.child } return result } var object = { name: 'one', child: { name: 'two', child: { name: 'three' } } } console.log(foo(object)) //=> ['one', 'two', 'three'] 

Answer 4

You could use a generator and curry the object and the numbers, you want.

 function setObject(object) { return function* (n) { while (n--) { yield object.name; object = object.child; } } } var obj = { name: 'one', child: { name: 'two', child: { name: 'three', child: { name: 'four', child: { name: 'five' } } } } }, getNumbers = setObject(obj); console.log([...getNumbers(4)]); 

 .as-console-wrapper { max-height: 100% !important; top: 0; } 

Answer 5

@stackoverfloweth's answer seemed the best to me as it is really simple and efficient. But I think it can be even simpler, and also I made it include the last level:

 var obj={ name:'one', child:{ name:'two', child:{ name:'three' } } } var res = []; function search(obj){ res.push(obj.name); !obj.child || search(obj.child); } search(obj); console.log(res); 

Answer 6

You could try something like this

funtion f1(array, obj){
  if(obj){
   if(obj.name){
     array.push(obj.name);
   }
   if(obj.child){
     return f1(array, obj.child);
   }
 }
 return array;
}


funtion f2(array, obj){
  while(obj){
    if(obj.name){
      array.push(obj.name);
    }
    obj = obj.child;

   }

   return array;
}

function foo(obj){
 var array = [];
 //recursive version
 return f1(array, obj); 
 // non recursive version
 //return f2(array, obj);
}

foo(obj);

Answer 7

Use the following recursive function getAllNames() :

 /** * Collects all `name` property values recursively * * @param o an object * @param res the resulting array * @returns {*|Array} */ function getAllNames(o, res) { var names = res || []; for (var k in o) { if (k === 'name') { names.push(o[k]); // saving `name` value } else if(k === 'child' && typeof o[k] === 'object') { getAllNames(o[k], names); // processing nested `child` object } } return names; } var obj = { name:'one', child:{ name:'two', child:{ name:'three', child: { name: 'four', child: { name: 'five' } } } } }; console.log(getAllNames(obj, [])); 

Answer 8

Many answers check for the undefined child as the argument of the function to terminate the recursion. This means an extra call which can be avoided

function doit (obj, arr = []){
    arr.push(obj.name);
    return obj.child ? doit(obj.child, arr) : arr;
}

Answer 9

This code will output array like this ["one", "two", "three"]

 var obj = { name: 'one', child: { name: 'two', child: { name: 'three' } } } var str = parser(obj); var arr = str.substring(0, str.length - 1).split(";"); console.log(arr); // Output ["one", "two", "three"] function parser(obj) { var text = obj.name + ";"; if (obj.child) text += parser(obj.child); return text; } 

Answer 10

Try this

var string = foo(obj);
var array = str.substring(0, str.length - 1).split(",");

console.log(array);

function foo(obj) {
  var total= obj.name + ",";
  if (obj.child !=null) total= total+ foo(obj.child);
  return total;
}