String to object in JS

Your string looks like a JSON string without the curly braces.

This should work then:

obj = eval('({' + str + '})');

If I'm understanding correctly:

var properties = string.split(', ');
var obj = {};
properties.forEach(function(property) {
    var tup = property.split(':');
    obj[tup[0]] = tup[1];
});

I'm assuming that the property name is to the left of the colon and the string value that it takes on is to the right.

Note that Array.forEach is JavaScript 1.6 -- you may want to use a toolkit for maximum compatibility.

Since JSON.parse() method requires the Object keys to be enclosed within quotes for it to work correctly, we would first have to convert the string into a JSON formatted string before calling JSON.parse() method.

var obj = '{ firstName:"John", lastName:"Doe" }';

var jsonStr = obj.replace(/(\w+:)|(\w+ :)/g, function(matchedStr) {
  return '"' + matchedStr.substring(0, matchedStr.length - 1) + '":';
});

obj = JSON.parse(jsonStr); //converts to a regular object

console.log(obj.firstName); // expected output: John
console.log(obj.lastName); // expected output: Doe

This would work even if the string has a complex object (like the following) and it would still convert correctly. Just make sure that the string itself is enclosed within single quotes.

var strObj = '{ name:"John Doe", age:33, favorites:{ sports:["hoops", "baseball"], movies:["star wars", "taxi driver"]  }}';

var jsonStr = strObj.replace(/(\w+:)|(\w+ :)/g, function(s) {
  return '"' + s.substring(0, s.length-1) + '":';
});

var obj = JSON.parse(jsonStr);
console.log(obj.favorites.movies[0]); // expected output: star wars

You need use JSON.parse() for convert String into a Object:

var obj = JSON.parse('{ "firstName":"name1", "lastName": "last1" }');

I'm using JSON5, and it's works pretty well.

The good part is it contains no eval and no new Function, very safe to use.

In your case, The short and beautiful code

Object.fromEntries(str.split(',').map(i => i.split(':')));

Here is my approach to handle some edge cases like having whitespaces and other primitive types as values

const str = " c:234 , d:sdfg ,e: true, f:null, g: undefined, h:name "; 

const strToObj = str
  .trim()
  .split(",")
  .reduce((acc, item) => {
    const [key, val = ""] = item.trim().split(":");
    let newVal = val.trim();

    if (newVal == "null") {
      newVal = null;
    } else if (newVal == "undefined") {
      newVal = void 0;
    } else if (!Number.isNaN(Number(newVal))) {
      newVal = Number(newVal);
    }else if (newVal == "true" || newVal == "false") {
      newVal = Boolean(newVal);
    }
    return { ...acc, [key.trim()]: newVal };
  }, {});

const text = '{"name":"John", "age":30, "city":"New York"}';
const myArr = JSON.parse(text);
document.getElementById("demo").innerHTML = myArr.name;

var stringExample = "firstName:name1, lastName:last1 | firstName:name2, lastName:last2";    

var initial_arr_objects = stringExample.split("|");
    var objects =[];
    initial_arr_objects.map((e) => {
          var string = e;
          var fields = string.split(','),fieldObject = {};
        if( typeof fields === 'object') {
           fields.forEach(function(field) {
              var c = field.split(':');
              fieldObject[c[0]] = c[1]; //use parseInt if integer wanted
           });
        }
            console.log(fieldObject)
            objects.push(fieldObject);
        });

"objects" array will have all the objects

I know this is an old post but didn't see the correct answer for the question.

var jsonStrig = '{';
      var items = string.split(',');
      for (var i = 0; i < items.length; i++) {
          var current = items[i].split(':');
          jsonStrig += '"' + current[0] + '":"' + current[1] + '",';
      }
      jsonStrig = jsonStrig.substr(0, jsonStrig.length - 1);
      jsonStrig += '}';
var obj = JSON.parse(jsonStrig);
console.log(obj.firstName, obj.lastName);

Now you can use obj.firstName and obj.lastName to get the values as you could do normally with an object.