Kebab file names

snippets/take-while.md

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+---
+title: Remove list elements while condition is met
+tags: array
+cover: colors-mural
+firstSeen: 2018-01-26T12:55:31+02:00
+lastUpdated: 2020-11-29T12:04:53+02:00
+---
+
+Removes elements in an array until the passed function returns `false`.
+Returns the removed elements.
+
+- Loop through the array, using a `for...of` loop over `Array.prototype.entries()` until the returned value from the function is falsy.
+- Return the removed elements, using `Array.prototype.slice()`.
+- The callback function, `fn`, accepts a single argument which is the value of the element.
+
+```js
+const takeWhile = (arr, fn) => {
+  for (const [i, val] of arr.entries()) if (!fn(val)) return arr.slice(0, i);
+  return arr;
+};
+```
+
+```js
+takeWhile([1, 2, 3, 4], n => n < 3); // [1, 2]
+```