Local Variables: Variables that are defined within a function or a block are called local variables. They can only be used within a function or a block. These can't be accessed outside their scope or ...

The variable i is declared using the let keyword. This ensures it is a local variable. Initially, its value is undefined, before the for loop assigns and modifies its value.

Parameter passing allows the values of local variables within a main program to be accessed, updated and used within multiple sub-programs without the need to create or use global variables.