Help with code writing Js

Question

Declare str, num, flag, and txt variables with Hello, 123, true, and true respectively. Use the type definition operator to make sure the variables are type: string, number, boolean.
Js studying recently need to complete a task write 1 example please I will do the rest myself.

Answer 1

All you need to do is

var your_variable_name = your_initial_value;

Answer 2

Where is your code?