The Modern JS Tutorial: Recursion and stack: Sum all numbers till the given one

	function sumToFromLoop(n) {
	let sum = 0;
	for(let i = 0; i <= n; i++) {
	sum += i;
	}
	return sum;
	}
	function sumToRecursion(n) {
	if (n === 1) {
	return n;
	}
	return n + sumToRecursion(n - 1);
	}
	function sumToFormula(n) {
	return n * (n + 1) / 2; // 👍🏻
	}
	console.log( sumToFromLoop(100) ); // 5050
	console.log( sumToRecursion(100) ); // 5050
	console.log( sumToFormula(100) ); // 5050

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