Why is Order Preserved in JSON Lists But Not Objects?

Preserving Order in JSON Lists

In JSON, the order of elements in objects is not guaranteed. However, many developers rely on the order being preserved for various reasons. In contrast to objects, the order of elements in JSON lists is explicitly intended to be maintained. This is specified in the JSON specification, RFC 7159, which states:

"An array is an ordered sequence of zero or more values."

The reason for this distinction is based on the intended use cases for each data type. Objects are unstructured collections of name-value pairs, while lists are ordered sequences of values. Preserving the order in lists is important for ensuring that the sequence of values is considered significant.

While some implementations may also preserve the order of object properties, this behavior is not guaranteed and should not be relied upon. Therefore, when dealing with JSON data, it's essential to be aware of the distinction in the order preservation behavior between objects and lists.

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