Changed original flatten to be named deepFlatten, added normal flatten, improved some other snippets.
291 B
291 B
Count occurrences of a value in array
Use reduce() to increment a counter each time you encounter the specific value inside the array.
const countOccurrences = (arr, value) => arr.reduce((a, v) => v === value ? a + 1 : a + 0, 0);
// countOccurrences([1,1,2,1,2,3], 1) -> 3