A JavaScript (ES6) implementation of printing all Permutations of a String

StringPermutations.js

// Print all permutations of a string in JavaScript (ES6)
// O(2^n) runtime

class StringSubsets {
	constructor(str) {
		this.str = str;
	}
	
	print() {
		const map = new Map();
		for (let ch of this.str) {
			map.set(ch, ((map.get(ch) || 0) + 1));
		}
		this.recurse(
			[...map.values()],
			[...map.keys()],
			new Array(this.str.length)	
		);
	}
	
	recurse(countMap, valuesMap, result, offset = 0, depth = 0) {
		while (offset < result.length) {
			if (countMap[offset] > 0) {
				countMap[offset]--;
				result[depth] = valuesMap[offset];
				console.log(result.join(''));
				this.recurse(countMap, valuesMap, result, offset, depth + 1);
				countMap[offset]++;
				result[depth] = '';
			}
			offset++;
		}
	}
}

const s = new StringSubsets("AABC");
s.print();


// OUTPUT
//A
//AA
//AAB
//AABC
//AAC
//AB
//ABC
//AC
//B
//BC
//C