When you declare a variable with the `var` keyword, it is declared globally, or locally if declared inside a function.
The `let` keyword behaves similarly, but with some extra features. When you declare a variable with the `let` keyword inside a block, statement, or expression, its scope is limited to that block, statement, or expression.
For example:
```js
var numArray = [];
for (var i = 0; i <3;i++){
numArray.push(i);
}
console.log(numArray);
console.log(i);
```
Here the console will display the values `[0, 1, 2]` and `3`.
With the `var` keyword, `i` is declared globally. So when `i++` is executed, it updates the global variable. This code is similar to the following:
```js
var numArray = [];
var i;
for (i = 0; i <3;i++){
numArray.push(i);
}
console.log(numArray);
console.log(i);
```
Here the console will display the values `[0, 1, 2]` and `3`.
This behavior will cause problems if you were to create a function and store it for later use inside a `for` loop that uses the `i` variable. This is because the stored function will always refer to the value of the updated global `i` variable.
```js
var printNumTwo;
for (var i = 0; i <3;i++){
if (i === 2) {
printNumTwo = function() {
return i;
};
}
}
console.log(printNumTwo());
```
Here the console will display the value `3`.
As you can see, `printNumTwo()` prints 3 and not 2. This is because the value assigned to `i` was updated and the `printNumTwo()` returns the global `i` and not the value `i` had when the function was created in the for loop. The `let` keyword does not follow this behavior:
```js
let printNumTwo;
for (let i = 0; i <3;i++){
if (i === 2) {
printNumTwo = function() {
return i;
};
}
}
console.log(printNumTwo());
console.log(i);
```
Here the console will display the value `2`, and an error that `i is not defined`.
`i` is not defined because it was not declared in the global scope. It is only declared within the `for` loop statement. `printNumTwo()` returned the correct value because three different `i` variables with unique values (0, 1, and 2) were created by the `let` keyword within the loop statement.
# --instructions--
Fix the code so that `i` declared in the `if` statement is a separate variable than `i` declared in the first line of the function. Be certain not to use the `var` keyword anywhere in your code.
This exercise is designed to illustrate the difference between how `var` and `let` keywords assign scope to the declared variable. When programming a function similar to the one used in this exercise, it is often better to use different variable names to avoid confusion.
