JavaScript TypeError – Invalid assignment to const “X”
This JavaScript exception invalid assignment to const occurs if a user tries to change a constant value. Const declarations in JavaScript can not be re-assigned or re-declared.
Message:
TypeError: invalid assignment to const "x" (Firefox) TypeError: Assignment to constant variable. (Chrome) TypeError: Assignment to const (Edge) TypeError: Redeclaration of const 'x' (IE)
Error Type:
TypeError
Cause of Error: A const value in JavaScript is changed by the program which can not be altered during normal execution.
Example 1: In this example, the value of the variable(‘GFG’) is changed, So the error has occurred.
HTML
<script> const GFG = "This is GFG"; // Error here GFG = "This is GeeksForGeeks"; </script> |
Output(in console):
TypeError: Assignment to const
Example 2: In this example, the value of the object(‘GFG_Obj’) is changed, So the error has occurred.
HTML
<script> const GFG_Obj = {key: 'val1'}; // Error here GFG_Obj = {key: 'val2'}; </script> |
Output:
TypeError: Assignment to const
