How to Convert a JavaScript Object to a Readable String?

How to Display a JavaScript Object in String Format

In JavaScript, it is often necessary to display the content of an object in a readable string format. Similar to the formatted output displayed when a variable is alerted, there are several methods available to achieve this.

SOLUTION 1: Using JSON.stringify()

The native JSON.stringify() method is the most straightforward approach. It converts the object into a JSON string that can be displayed or alerted.

const obj = {
  name: "John Doe",
  age: 30
};

const str = JSON.stringify(obj);
console.log(str); // Output: {"name":"John Doe","age":30}

To beautify the output with indentation, pass a null value as the second argument.

const str = JSON.stringify(obj, null, 4); // Output:
{
    "name": "John Doe",
    "age": 30
}

SOLUTION 2: Custom JSON.stringify Replacer (for Circular Structures)

If an object contains circular structures, JSON.stringify() might throw an error. In such cases, a custom replacer function can be used.

const obj = {
  name: "John Doe",
  age: 30,
  children: [
    obj // Circular reference
  ]
};

const replacer = (key, value) => {
  if (value === obj) {
    return "[Circular]";
  }
  return value;
};

const str = JSON.stringify(obj, replacer);
console.log(str); // Output: {"name":"John Doe","age":30,"children":["[Circular]"]}

The custom replacer ensures that the circular structure is replaced with a descriptive string to avoid the error.

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