Intellij is complaining about this code, not sure why

[lusty sinew]

    public K get(int i) {
        int j = 0;
        this.forEach((K key, V value) -> {
            if (j == i) {
                return key;
            }
            j++;
        });
        return null;
    }```
its saying "variable used in lambda expression should be final or effectively final" (about j), and gives the option to convert j to atomic. Im wondering what that means, and what atomic is. (K and V are generics, this class extends HashMap)

[slender agate]

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[slow bane]

Inside a lambda, you can't reassign a local variable that was declared outside of that lambda.
Here you're reassigning j in the lambda, despite it's a local variable declared in get(). That doesn't work

IntelliJ offers to replace with an AtomicInteger, because then you wouldn't need to reassign it. You would just need to call a method to update it.

That is, however, a hacky solution that shouldn't be used. In your case, that wouldn't even solve the entire problem

Indeed, you're trying to return from inside the lambda, which can't be done either

Your better bet is to get rid of the lambda altogether, and to iterate over the Map's entries instead.

[lusty sinew]

Im not sure how to do that

[slow bane]

for(Map.Entry<K, V> entry : this.entrySet()) {

(Come to think of it, the better solution is to stream the keys, skip i-1 of them, and return the first found in the rest)

[lusty sinew]

something like this? java for (K key : this.keySet()) { if (j == i) return key; j++; }

[slow bane]

Yeah, it's even better

[lusty sinew]

cool, thanks

[slender agate]

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