add isNegativeZero

snippets/isNegativeZero.md

@@ -0,0 +1,14 @@
+### isNegativeZero
+
+Checks if the given value is a negative zero `-0`.
+
+Checks whether a passed value is equal to `0` and if one devided by the value equals `-Infinity`.
+
+```js
+const isNegativeZero = val => val === 0 && 1 / val === -Infinity;
+```
+
+```js
+isNegativeZero(-0); // true
+isNegativeZero(0); // false
+```