JavaScript TypeError - Can't redefine non-configurable property "x"

This JavaScript exception can’t redefine non-configurable property occurs if user tries to redefine a property, but that property is non-configurable.

Message:

TypeError: Cannot modify non-writable property {x} (Edge)
TypeError: can't redefine non-configurable property "x" (Firefox)
TypeError: Cannot redefine property: "x" (Chrome)

Error Type:

TypeError

Cause of the Error: If there is an attempt to redefine a property, but that property is non-configurable.

Example 1: In this example, the ‘prop1’ is being attempted to change the value, so the error has been occurred.

HTML

<script> 
var GFG_Obj = Object.create({}); 
Object.defineProperty(GFG_Obj, "prop1", {value: "val1"});  
Object.defineProperty(GFG_Obj, "prop1", {value: "val2"}); 
</script>

Output:

TypeError: Cannot modify non-writable property 'prop1'

Example 2: In this example, the ‘prop2’ is being attempted to change the value, So the error has occurred.

HTML

<script> 
var Obj = Object.create({"prop1": "val1"}); 
Object.defineProperty(Obj, "prop2", {value: "val21"});  
Object.defineProperty(Obj, "prop2", {value: "val22"}); 
</script>

Output:

TypeError: Cannot modify non-writable property 'prop2'

My Personal Notes

Recommended Posts:

PranchalKatiyar

Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.