Why Can\'t You Add Properties to JavaScript Strings?

JavaScript's String Primitives: Unmodifiable but Versatile

In JavaScript, strings are among the seven primitive types that cannot have properties added to them. This fundamental characteristic of strings plays a vital role in their usage and the limitations they present.

Primitive vs. Non-Primitive Types

JavaScript distinguishes between primitive types and the non-primitive type, Object. Primitive types include Undefined, Null, Boolean, Number, BigInt, String, and Symbol. Values of primitive types, known as primitive values, are immutable and cannot possess properties. On the other hand, the Object data type encompasses non-primitive values, which are mutable and can have properties defined on them.

Attempting to Add Properties to Strings

As an illustration, consider the following code:

var test = "test";
test.test = "test inner";
console.log(test);
console.log(test.test);

Running this code reveals an absence of properties on the string test. The attempted assignment of 'test inner' as a property on 'test' is a no-op because strings are immutable.

Workarounds for Date Sorting in a Grid

To address the need for date sorting within the grid that binds only to strings/numbers, customizable formatting can be explored. Extend the existing date formatting function to include a special character or prefix that signifies a date value. This allows the grid to identify and sort these values as dates without modifying the underlying data type.

Alternative Solution: Utilize Date Objects

While customizing the formatting is a workaround, it is worth considering utilizing Date objects for date handling. Binding to Date objects provides access to native date sorting capabilities, simplifies date manipulation, and ensures alignment with standard date notations.

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