frontend-avond-javascript-oefeningen/doubloon.js

function isDoubloon (word) {
	word = word.toLowerCase

	for (let i = 0; i < word.length; i++) {
		let testletter1 = word[i];
		let count = 0;
			for (let j = 0; j < word.length; j++) {
				let testLetter2 = word[j];
				if (testletter1 === testLetter2) {
					count++
				}
			}
			if (count != 2) {
				return false;
			}
	}


	return true;
}

console.log(isDoubloon('abbaa'));