JavaScript: Validate whether a given value type is pure json object or not

Last update on July 18 2025 13:03:29 (UTC/GMT +8 hours)

JavaScript validation: Exercise-7 with Solution

Validate Pure JSON Object

Write a JavaScript function to validate whether a given value type is a pure JSON object or not.

Sample Solution: -

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JavaScript function to validate whether a given value type is pure json object or not.</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function is_json(value)
        {
        return toString.call(value) === '[object Object]';
        }

console.log(is_json({name: 'Robert'}));

console.log(is_json('bar'));

console.log(is_json(72));

Sample Output:

true
false
false

Flowchart:

Live Demo:

See the Pen javascript-validation-exercise-7 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

Write a JavaScript function that checks if a given value is a plain JSON object using Object.getPrototypeOf() and comparing it to Object.prototype.
Write a JavaScript function that validates whether an object was created by the Object constructor and not through custom prototypes.
Write a JavaScript function that distinguishes between a JSON object and other objects like arrays or Date objects.
Write a JavaScript function that accepts an input and returns true if it is a pure JSON object (no inherited properties besides those from Object.prototype).

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