What is the ! operator (non-null assertion) used for in a template?

In Angular, the ! operator (non-null assertion) in a template is used to tell the TypeScript compiler that a value is definitely not null and not undefined, even if the variable's type allows those values.

#Main points

1. Syntax in a template:

• Tells Angular: "I am sure that user exists at render time."
• The compiler will not raise the error "Object is possibly 'null' or 'undefined'".

2. Use with bindings:

• Allows using an object's properties without additional null checks.

3. Important to understand:

• This is only an assertion for the compiler.
• If the value actually turns out to be null or undefined at runtime, the error will still occur.

In other words, ! is a way to bypass TypeScript's strict type checking when the developer is sure the value is present.