Tests whether this object has the specified property as a direct property.
Tests whether this object has the specified property as a direct property.
Unlike js.Object.hasProperty, this method does not check down the object's prototype chain.
MDN
Tests whether this object is in the prototype chain of another object.
Tests whether this object is in the prototype chain of another object.
Human-readable description of the error
Human-readable description of the error
MDN
Tests whether the specified property in an object can be enumerated by a call to js.Object.properties, with the exception of properties inherited through the prototype chain.
Tests whether the specified property in an object can be enumerated by a call to js.Object.properties, with the exception of properties inherited through the prototype chain. If the object does not have the specified property, this method returns false.
MDN
Represents an error when a non-existent variable is referenced.
A ReferenceError is thrown when trying to dereference a variable that has not been declared.
MDN