Knowledge MaxxingTypeScript type
A TypeScript type describes the shape of a value, such as which properties an object has or what kind of data a variable can hold, checked before the code ever runs.
Prerequisite: JavaScript variable
What matters
Because types are checked ahead of time, many mistakes, like passing the wrong kind of value to a function, are caught while writing code instead of discovered later at runtime.
Example
Declaring a function parameter as 'name: string' lets TypeScript flag an error immediately if the function is called with a number instead.
Common misconception
TypeScript types do not exist at runtime in the final JavaScript; they are checked only while writing and compiling the code, then stripped out entirely.
Recall question
When are TypeScript's type checks actually performed, relative to when the code runs?