document.exists()

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Test if a collection document exists.

Signature

exists() => Boolean

Description

The exists() method tests if a collection document exists.

exists() vs. null comparisons

You can use either exists() or a null comparison (== null or != null) to check the existence or validity of a value. For example:

Product.byId("111").exists()  // true

Product.byId("111") != null   // true

Key differences:

  • exists() returns an error if called on an unsupported value.

  • Null comparisons do not throw errors and work safely on any value.

For example:

// Declare an object. Objects don't support
// an `exists()` method.
let object = { a: "Foo", b: "Bar" }

object.exists()  // Returns `invalid_query` error

object != null   // Returns true

Parameters

None

Return value

Type Description

Boolean

true = The document exists.
false = The document doesn’t exist.

Examples

Product.byId("222").exists()
true
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