JsonVariantConst::isNull()

Description

JsonVariantConst::isNull() tests if the JsonVariantConst is unbound or points to a null value.

Remember that a JsonVariant is a reference to a value in a JsonDocument. A JsonVariant that is not attached to a JsonDocument will always be null:

JsonVariantConst variant; variant.isNull(); // returns true 

As an alternative, you can use the conversion to bool; for example, if(variant) instead of if(!variant.isNull())

Signature

bool isNull() const; 

Return value

• true if the JsonVariantConst is unbound or points to a null.
• false if the JsonVariantConst is valid and points to a non-null value.

See also

• JsonVariant::isNull()