Non-null Assertion

The non-null assertion operator in TypeScript is a way to tell the compiler that you are certain a value is not null or undefined, even if the TypeScript's type checker thinks it could be. It is denoted by an exclamation mark (!) placed after a variable or expression. Using this operator effectively tells the compiler to suppress strict null checks for that particular expression, trusting that you, the developer, have enough context to know the value will be present at runtime.