How to Change a Value Type Return Value That Can't Be Modified

This document explains how to work around a limitation in the object-oriented programming language JavaScript and change a value type return value that cannot be modified. As a developer, you will encounter situations where you encounter an error due to a value type that cannot be modified. This guide provides step-by-step instructions to help you work around the error and modify the value type.


  • Comfort with the JavaScript language
  • Basic understanding of types, objects, and methods

Step-by-Step Guide

Identify the immutable value type return value that you need to change.

Convert the value type into a mutable object, such as an array or a dictionary.

Modify the object as necessary, such as adding or deleting elements, or changing their value.

  1. Convert the object back into the original value type.


Q: When I convert a value type into an object and modify it, can I change all of the values it contains?

A: Yes, you can modify any of the values within the object. However, you should be careful not to change the object's structure or the values it contains in a way that would not be supported by the original value type.

Q: Is there a simpler way to modify a value type return value that can't be modified?

A: Generally, no. In most cases, the only way to modify an immutable value type return value is to convert it into a mutable object and then convert it back into the original value type.


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