Javascript 如何递归地materialized 一个字符串

发布于05月16日

在try 更自如地使用递归函数的同时，我try 编写一个函数，该函数接受一个以点分隔的字符串，并将其转换为一个对象.

{
  user: {
    first: {
      name: 'robert'
    }
  }
}

以下是我的try :

function objectifyHelper(array, object) {
    if (array.length === 2) {
        const [key, value] = array;
        object[key] = value;
        return object;
    } else {
        object[array[0]] = objectifyHelper(array.slice(1), object); 
        return object;
    }
}

function objectify(string) {
    const tokens = string.split('.');
    return objectifyHelper(tokens, {});
}

const str = 'user.first.name.robert';
const result = objectify(str);

这让我得到了以下结果:

result <ref *1> {
  name: 'robert',
  first: [Circular * 1],
  user: [Circular * 1]
}

我做错了什么？

推荐答案

你就快到了.然而，如果助手接受一个对象但也返回它，那么在递归调用中要保持一致

function objectifyHelper(array, object) {
    if (array.length === 2) {
        const [key, value] = array;
        object[key] = value;
        return object;
    } else {
        object[array[0]] = objectifyHelper(array.slice(1), {}); 
        return object;
    }
}

function objectify(string) {
    const 到kens = string.split('.');
    return objectifyHelper(到kens, {});
}

const str = 'user.first.name.robert';
const result = objectify(str);

console.log(result)

请注意，这只会改变您的

object[array[0]] = objectifyHelper(array.slice(1), object);

到

object[array[0]] = objectifyHelper(array.slice(1), {});

Reading OP's comment under the question, I believe it's fair 到 further expand the answer.

Yes, passing the newly created object 到 the recursive function and then returning it is could be simplified. One of possible approaches would be 到 remove the need 到 pass the object in到 the function and just return a newly created object 到 the caller.

因此，简化的版本将是

function objectifyHelper(array) {
    // we always create a new object
    var object = {};
    if (array.length === 2) {
        const [key, value] = array;
        object[key] = value;
    } else {    
        object[array[0]] = objectifyHelper(array.slice(1)); 
    }
    // and return it
    return object;
}

function objectify(string) {
    const 到kens = string.split('.');
    return objectifyHelper(到kens);
}

const str = 'user.first.name.robert';
const result = objectify(str);

console.log(result);