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snippets/js/s/sum-n.md

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+---
+title: Sum of numbers until n
+type: snippet
+language: javascript
+tags: [math]
+cover: blue-flower
+dateModified: 2020-10-22T20:24:30+03:00
+---
+
+Sums all the numbers between `1` and `n`.
+
+- Use the formula `(n * (n + 1)) / 2` to get the sum of all the numbers between 1 and `n`.
+
+```js
+const sumN = n => (n * (n + 1)) / 2;
+```
+
+```js
+sumN(100); // 5050
+```