Sometimes, we may run into the ‘TypeError: can’t define property "x": "obj" is not extensible’ when we’re developing JavaScript apps.
In this article, we’ll look at how to fix the ‘TypeError: can’t define property "x": "obj" is not extensible’ when we’re developing JavaScript apps.
Fix the ‘TypeError: can’t define property "x": "obj" is not extensible’ When Developing JavaScript Apps
To fix the ‘TypeError: can’t define property "x": "obj" is not extensible’ when we’re developing JavaScript apps, we should make sure we’re trying to add properties to an object that’s not extensible.
An object isn’t extensible after we called Object.preventExtensions on it.
On Edge, the error message for this error is TypeError: Cannot create property for a non-extensible object.
On Firefox, the error message for this error is TypeError: can't define property "x": "obj" is not extensible.
And on Chrome, the error message for this error is TypeError: Cannot define property: "x", object is not extensible.
For instance, we’ll get this error if we write:
'use strict';
const obj = {};
Object.preventExtensions(obj);
obj.x = 'foo';
Since we called Object.preventExtensions on obj before we tried to all the x property to obj.
Instead, we write:
'use strict';
const obj = {};
obj.x = 'foo';
Object.preventExtensions(obj);
to add the x property before we call Object.preventExtensions.
Conclusion
To fix the ‘TypeError: can’t define property "x": "obj" is not extensible’ when we’re developing JavaScript apps, we should make sure we’re trying to add properties to an object that’s not extensible.
An object isn’t extensible after we called Object.preventExtensions on it.
On Edge, the error message for this error is TypeError: Cannot create property for a non-extensible object.
On Firefox, the error message for this error is TypeError: can't define property "x": "obj" is not extensible.
And on Chrome, the error message for this error is TypeError: Cannot define property: "x", object is not extensible.
