TypeScript for Beginners - Object Casting

The video tutorial explains the concept of object casting and interfaces. It begins by defining an employee interface with an ID field and creating variables E1 and E2. E1 is an employee with a single property, while E2 has additional properties. The tutorial demonstrates assigning E2 to E1 without issues, but highlights problems when assigning E1 to E2 due to missing properties. It emphasizes that typecasting works only if the type members of the first variable are contained within the second variable.

What is the primary purpose of defining an interface in the context of object casting?

• To create a new data type

• To allow objects to inherit properties

• To enable dynamic typing

• To enforce a specific structure on objects

When creating a variable 'E1' that subscribes to the 'employee' interface, what property must it have?

• Address

• Name

• Salary

• ID

Why can 'E2' be assigned to 'E1' without issues?

• Because 'E2' has fewer properties than 'E1'

• Because 'E2' has all the properties of 'E1' and more

• Because 'E2' has the same properties as 'E1'

• Because 'E2' and 'E1' are of different types

What is the main reason 'E1' cannot be assigned to 'E2'?

• E1 is a constant and cannot be reassigned

• E1 and E2 are incompatible types

• E1 lacks some properties that E2 requires

• E1 has more properties than E2

What must be true for the data of one variable to be assigned to another in typecasting?

• The first variable must have more properties

• Both variables must have the same properties

• The first variable must be a subclass of the second

• The second variable must have all properties of the first