That's a variant of the "dot" operator allowing you to access attributes … October 15, 2019 3 min read 859. A non-null assertion is essentially you telling the compiler "I know it's not null so let me use it as though it's not null". The Angular non-null assertion operator causes the TypeScript type checker to suspend strict null and undefined checks for a specific property expression. operator evaluates to undefined or null, its right-hand side is returned. It just tells TypeScript that the value is never going to be null. class Student Since TypeScript is built on top of JavaScript, it has to handle the craziness of how JavaScript compare. Actual behavior: Currently as the code stands typescript is not able to warn us of the oncoming failure. src/app/app.component.html content_copy