Null

The null keyword represents a value indicating that there is no value.

let text: string = null;

What can be null

A string, an array, any, and a type you declare can hold null. The integer and floating point types, bool and char cannot, so assigning null to one is an error.

let text: string = null;
let items: i32[] = null;
let value: any = null;

An integer, a float, a bool or a char has no such value.

let count: i32 = null;

Null needs a type

null says nothing about the type a variable should have, so a let with only null to go on is an error. Write the type down.

let text = null;

let text: string = null;