When you try to access attributes on a primitive-typed value, such as a string, in JavaScript, you will encounter an error. This error occurs because primitive values, like strings, numbers, booleans, null, and undefined, are not objects and do not have attributes or properties.
Here is an example to illustrate this error:
let name = "John";
console.log(name.length);
In this example, we are trying to access the “length” attribute of the string value “John” using the dot notation. However, since “John” is a primitive string value, not an object, it does not have any attributes or methods. As a result, this code will throw an error: “Uncaught TypeError: Cannot read property ‘length’ of undefined”.
To avoid this error, you can convert the primitive value to an object using the corresponding wrapper object for the primitive type. For example, you can wrap a string in a String object like this:
let name = new String("John");
console.log(name.length); // Output: 4
By creating a String object, we can now access the “length” attribute of the string because the object now has properties and methods related to strings.