jsAssignment to constant variable.

In JavaScript, when you try to assign a value to a variable declared with the `const` keyword, you will get an error because `const` variables are read-only and cannot be reassigned once they are initialized. This error is called "Assignment to constant variable."

Here's an example:

const myVariable = 10;
myVariable = 20; // This will throw an error: "TypeError: Assignment to constant variable."

To fix this error, you can either change the variable declaration to `let` if you need to reassign the variable, or modify the existing value of the `const` variable without reassigning it.

let myVariable = 10;
myVariable = 20; // This is valid because 'myVariable' is declared using 'let'.

const myConstant = 10;
// Modify the existing value of 'myConstant' without reassignment
myConstant = 20; // This will throw an error: "TypeError: Assignment to constant variable."

Remember, `const` variables are meant for values that should not be changed after initialization.