How do I loop a cypress testcase and use the loop control variable?

Question

I'm repeating a cypress testcase with a for loop. Within the testcase I'm trying to use the loop control variable.

As an illustration the following (simplified) example:

for(var i = 0; i < 3; i++) {    
    it("Loop", () => { 
        cy.log("Value of i: " + i)
    })
}

The following output is generated:

Value of i: 3
Value of i: 3
Value of i: 3

That is not what I expected...

After a little trial and error I found out, that declaring a constant helps:

for(var i = 0; i < 3; i++) {    
    const loopCount = i
    it("Loop", () => { 
        cy.log("Value of loopCount: " + loopCount)
    })
}

This time the following output is generated:

Value of loopCount: 0
Value of loopCount: 1
Value of loopCount: 2

What exactly is happening here? Is using a constant the right way or is there a better approach?