How to Convert String to Array of Objects JavaScript ?

Given a string, the task is to convert the given string to an array of objects using JavaScript. It is a common task, especially when working with JSON data received from a server or API.

Below are the methods that allow us to convert string to an array of objects:

Using JSON.parse() Method

If the string is in JSON format, you can use the JSON.parse() method to convert it into an array of objects. JSON.parse() method converts the JSON string into an array of objects. The string must be in valid JSON format for JSON.parse() to work correctly.

Example: Parsing JSON String to Array of Objects which involves parsing a JSON string into an array of objects and then logging the resulting array.

const str = 
    '[{"name":"xyz", "age":30}, {"name":"abc", "age":25}]';

const arrayOfObjects = JSON
    .parse(str);

console.log(arrayOfObjects);

[ { name: 'xyz', age: 30 }, { name: 'abc', age: 25 } ]

Using String Splitting and Object Construction

If the string is not in JSON format, you can manually split the string and construct objects to create the array, split() method splits the string into an array of individual records based on the semicolon delimiter. The map() is used to iterates over each record and splits it into name and age using the comma delimiter. An object is constructed for each record with name and age properties, and age is converted to an integer using parseInt(age).

Example: Converting String Records to Array of Objects it involves splitting a string of records, mapping each record to an object with name and age properties, and then logging the resulting array of objects.

const dataString = 'xyz, 30; abc, 25';
const records = dataString
    .split(';');

const arrayOfObjects = records
    .map(record => {
        const [name, age] = record
            .split(',');
        return { name, age: parseInt(age) };
    });

console.log(arrayOfObjects);

[ { name: 'xyz', age: 30 }, { name: ' abc', age: 25 } ]

Using Regular Expressions

For more complex string formats, you can use regular expressions to extract data and convert it into an array of objects. The regular expression /Name: ([^,]+), Age: (\d+)/g is used to match the pattern in the string. The while loop iterates over each match found by the regular expression. For each match, an object is constructed with name and age properties, and age is converted to an integer using parseInt(match[2]). The object is then added to the arrayOfObjects.

Example: Converting JSON String to Array of Objects it involves parsing a JSON string into an array of objects.

const str = 'Name: xyz, Age: 30; Name: abc, Age: 25';
const regex = /Name: ([^,]+), Age: (\d+)/g;
const arrayOfObjects = [];
let match;
while ((match = regex
    .exec(str)) !== null) {
    arrayOfObjects
        .push({
            name: match[1],
            age: parseInt(match[2])
        });
}

console.log(arrayOfObjects);

[ { name: 'xyz', age: 30 }, { name: 'abc', age: 25 } ]

Using Custom Delimiters and Object Construction

Another approach to convert a string to an array of objects is to use custom delimiters and object construction. This method is particularly useful when the string format doesn't follow a strict JSON structure but contains well-defined patterns or delimiters. By splitting the string based on these custom delimiters, we can construct objects and create the desired array.

Example: The following example demonstrates how to convert a string with custom delimiters into an array of objects.

const inputString = "name:John,age:30|name:Jane,age:25|name:Bob,age:35";

function stringToArrayOfObjects(str) {
    return str.split('|').map(record => {
        const properties = record.split(',');
        const obj = {};
        properties.forEach(property => {
            const [key, value] = property.split(':');
            obj[key.trim()] = isNaN(value) ? value.trim() : parseInt(value);
        });
        return obj;
    });
}

const arrayOfObjects = stringToArrayOfObjects(inputString);
console.log(arrayOfObjects);

[
  { name: 'John', age: 30 },
  { name: 'Jane', age: 25 },
  { name: 'Bob', age: 35 }
]

Using Mapping and Filtering Functions

This method involves using map and filter functions to handle strings with a custom format, which can be especially useful if you need to preprocess the data before constructing objects.

Example: In this example we defines a function to parse a string of records into an array of objects. It splits the input string by ;, processes each record, and handles properties to create the final array.

const inputString = "Name:John, Age:30; Name:Jane, Age:25; Name:Bob, Age:35";
function parseStringToArrayOfObjects(str) {
    const records = str.split(';').map(record => record.trim()).filter(Boolean);
   
    const objectsArray = records.map(record => {
        const properties = record.split(',').map(prop => prop.trim());
        const obj = properties.reduce((acc, property) => {
            const [key, value] = property.split(':').map(part => part.trim());
            acc[key] = isNaN(value) ? value : parseInt(value, 10);
            return acc;
        }, {});
        
        return obj;
    });

    return objectsArray;
}

const arrayOfObjects = parseStringToArrayOfObjects(inputString);

console.log(arrayOfObjects);

[
  { Name: 'John', Age: 30 },
  { Name: 'Jane', Age: 25 },
  { Name: 'Bob', Age: 35 }
]