Introduction to TypesScript

Introducing TypeScript

In programming, the type variable data indicates the set of values that are valid for that data. For example, if a variable is an integer, we would expect the variable to have a value such as 1, -3, or 357 and not a value like banana. If the variable is set to a value that is not of the expected type, we think that something bad will happen. In some languages, attempting to set data to the wrong value leads to a compiler error, in other languages it leads to incorrect or unspecified behavior at runtime.

All high-level programming languages use some concept of type to determine behavior, which is to say that all these languages determine behavior by using not just the value of a variable in the system but also information about what kind of value it is.

TypeScript is a superset of JavaScript that allows us to optionally add annotations to the code to specify type information. ...