Run results for: getCasePermutationsLongerArrayOnly

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/112.0

Browser: Firefox 112

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Array version	7209.7 Ops/sec
String version	12903.0 Ops/sec

Script Preparation code:

function getCasePermutations(S, idx, substr, result) {
	if (idx === S.length) {
		result.push(substr);
		return;
	}

	const char = S[idx];
	const nextIdx = idx + 1;

	if (char >= '0' && char <= '9') {
		getCasePermutations(S, nextIdx, substr + char, result);
		return;
	}
	getCasePermutations(S, nextIdx, substr + char.toLowerCase(), result);
	getCasePermutations(S, nextIdx, substr + char.toUpperCase(), result);

	return result;
}

function getCasePermutationsArr(S, idx, subStrArr, result) {
	if (idx === S.length) {
		result.push(subStrArr.join(''));
		return;
	}

	const char = S[idx];
	const nextIdx = idx + 1;

	if (char >= '0' && char <= '9') {
		subStrArr.push(char);
		getCasePermutationsArr(S, nextIdx, subStrArr, result);
		subStrArr.pop();
		return;
	}
	subStrArr.push(char.toLowerCase());
	getCasePermutationsArr(S, nextIdx, subStrArr, result);
	subStrArr.pop();

	subStrArr.push(char.toUpperCase());
	getCasePermutationsArr(S, nextIdx, subStrArr, result);
	subStrArr.pop();

	return result;
}

Tests:

Array version
const testString = "a1b2c3d4e5f6g7h8i9j0"; getCasePermutationsArr(testString, 0, [], [])
String version
const testString = "a1b2c3d4e5f6g7h8i9j0"; getCasePermutations(testString, 0, '', [])

Run results for: getCasePermutationsLongerArrayOnly

Array version

String version