How do I convert a string to a dictionary in javascript?-CodePudding

I have a string

var str = "1:6,5,2,2:3";

I want to convert this str into a js dictionary such that:

var dict = {1:"6,5,2",
            2:"3"};

so that I can fetch the values by their respective key index. How do I convert it?

I had tried this code to store the splitted values into an array:

var pages = "1:6,5,2,2:3";
var numbers = [];
if (pages.includes(',')) {
  page_nos = pages.split(',');
  for (var i = 0; i < page_nos.length; i  ) {
    if (page_nos[i].includes(':')) {
      var n = page_nos[i].split(':');
      numbers.push(n[1]);
    } else {
      numbers.push(page_nos[i]);
    }
  }
} else {
  page_nos = pages.split(':');
  numbers.push(page_nos[1])
};

console.log('numbers: ', numbers);

But it's incorrect, as without dictionary it's impossible to know what value belongs to which index

CodePudding user response：

If you cannot make your input string a proper JSON or another easily parsable format in the first place, this answers your question:

const str = "1:6,5,2,2:3";

const obj = str.split(/,(?=\d :)/).reduce((accu, part) => {
  const [k, v] = part.split(':', 2);
  accu[k] = v;
  return accu;
}, {});
console.log(obj);

Cut the string at all commas that are followed by digits and a colon. Each part has a key in front of a colon and a value after it, which should be stuffed in an object in this format.

CodePudding user response：

No mutations solution.

const str = "1:6,5,2,2:3";

const dict = str
  .split(/(\d :.*)(?=\d :)/g)
  .reduce((t, c) => {
    const [key, value] = c.replace(/,$/, "").split(/:/);
    return { ...t, [key]: value }
  });

  
console.log(dict);

CodePudding user response：

if you consider not using regular expression, you might try this as well. to take out a dict (Object) from that string, this will do.

var pages = "1:6,5,2,2:3";

function stringToObject(str) {
    
  var page_object = {};

  var last_object;

  str.split(",").forEach((item) => {
    if (item.includes(":")) {
      page_object[item.split(":")[0]] = item.split(":")[1];

      last_object = item.split(":")[0];
    } else {
      page_object[last_object]  = `,${item}`;
    }
  });
  return page_object;
}

console.log(stringToObject(pages))

CodePudding user response：

Presented below may be one possible solution to achieve the desired objective.

NOTE: In lieu of var the code uses either let or const as applicable.

Code Snippet

const pages = "1:6,5,2,2:3";
const resObj = {};
let page_nos, k;
if (pages.includes(',')) {
  page_nos = pages.split(',');
  for (let i = 0; i < page_nos.length; i  ) {
    if (page_nos[i].includes(':')) {
      let n = page_nos[i].split(':');
      k = n[0];
      resObj[k] = n[1].toString();
    } else {
      resObj[k]  = ", "   page_nos[i].toString();
    }
  }
} else {
  page_nos = pages.split(':');
  resObj[page_nos[0]] = [page_nos[1]]
  numbers.push(page_nos[1])
};

console.log('result object: ', resObj);

This code essentially fixes the code given in the question. It is self-explanatory and any specific information required may be added based on questions in comments.

CodePudding user response：

You could take nested splitring for entries and get an object from it.

const
    str = "1:6,5,2,2:3",
    result = Object.fromEntries(str
        .split(/,(?=[^,]*:)/)
        .map(s => s.split(':'))
    );

console.log(result);