isSet()

isSet(value): value is Set<unknown>

Checks if a value is a Set instance.

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Parameters

value: unknown

The value to check.

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Returns: value is Set<unknown>

true if the value is a Set, false otherwise.

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See Also

• isMap
• isWeakSet

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Since

2.0.0

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Example

isSet(new Set());        // => true
isSet(new Set([1, 2]));  // => true
isSet([]);               // => false
isSet(new WeakSet());    // => false
isSet(new Map());        // => false

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How it works?

Type guard that checks if a value is a Set.

Type Narrowing

Common Checks

Value	Result
new Set()	true
new Set([1, 2, 3])	true
new WeakSet()	false
[]	false
{ add: () => {} }	false

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Use Cases

Identify unique collections 📌

Check if a value is a Set instance. Useful when working with collections that require uniqueness.

#identify#Set#unique#collections#deduplication#membership

if (isSet(items)) {
  console.log(items.has(value));
}