The Strict compiler option enforces the strict type checking in TypeScript by enabling all the strict type rules under the strict family. The helps us to enable strict type checking without having to enable each compiler option separately. Note that future Typescript versions may introduce additional stricter checking options & enable them by default under this flag.
TypeScript has two special values for Null and Undefined. Both represent no value or absence of any value. The difference between Null & Undefined is subtle and confusing. Prior to TypeScript 2.0, we could assign them all other types like numbers, strings, etc. Such assignment has been the source of a lot of errors likeTypeErrors or ReferenceErrors in JavaScript. The StrictNullChecks introduced in version 2.0 raises compile-time errors if we use Null or Undefined. In this tutorial, we compare Null and Undefined. let us learn the similarities and differences etc.
StrictNullChecks in TypeScript introduces stricter type checks for null & undefined. This option was introduced in TypeScript 2.0. We enable it by setting  strictNullChecks: true in the tsconfig.json, which ensures that the compiler will raise an error if we assign Null and Undefined to other types.
The null in TypeScript is a special value & also a data type. The value null represents the intentional absence of any object value. It is one of TypeScript’s primitive values and is treated as falsy for boolean operations. The value of null is represented in using the literal null.
Undefined is a special value and also a data type in TypeScript. TypeScript also has a global variable with the name undefined which has the value Undefined. Undefined is a primitive values and is treated as falsy for boolean operations. In this tutorial let us learn how to use undefined in TypeScript.
