how to declare typesccript boolean in a class code example

Example 1: how to declare a boolean in typescript

let isDone: boolean = false;

Example 2: typescript default value for boolean

// undefined, as well as false, are both falsy values that you can test the same way.
export class ReccurrenceModel {
    ...
    isMonday = false;
    isTuesday = false;
    ...
}