typescript const or let code example

Example 1: let vs const

`const` is a signal that the identifier won't be reassigned.

`let` is a signal that the variable may be reassigned, such as a counter in a
loop, or a value swap in an algorithm.

It also signals that the variable will be used only in the block it's defined
in, which is not always the entire containing function.

Example 2: variable declare in ts

let a:number =1
let b:Boolean = true
let c:string = "Grepper"