What is the Difference Between SpreadElement and Spread Syntax in ECMAScript?

What is the SpreadElement in ECMAScript Documentation?

The SpreadElement, defined in the ECMAScript specification as:

SpreadElement[Yield]:
...AssignmentExpression[In, ?Yield]

is synonymous with the Spread syntax described in MDN documentation.

Spread Syntax and Its Use Cases

Spread syntax allows iterables, such as arrays, strings, or objects, to be expanded in various contexts. These Use cases include:

• Function calls: The spread operator can expand iterables into argument lists for function calls. For example:

myFunction(...iterableObj);

• Array literals: Spread syntax can be used to concatenate arrays. For example:

[...iterableObj, 4, 5, 6]

• Object literals: Spread syntax can be used to merge objects. For example:

{...iterableObj, key1: value1}

SpreadElement vs. Spread Syntax

While both terms refer to the same functionality, there is a subtle distinction in semantics and usage.

• SpreadElement is a token that appears within an expression. It expands an iterable into individual elements during evaluation.
• Spread syntax refers to the broader use of the spread operator (...). It encompasses different contexts where iterables can be expanded, including function calls, array literals, and object literals.

Additional Notes

It's important to note that using the term "spread operator" can be misleading, as it is not an operator in the conventional sense but rather a punctuation token that serves different roles depending on the context.

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