Array Flatenner

1/* Example with reducer */
2private flatten = (arr: any): any => {
3   return arr.reduce((acc: any, arr: any) => [...acc, ...arr], []);
4}
5export default flatten;
6
7/* ES2019 Update - flat() */
8const arr = [1,2,[1,2],[2,3]]; 
9const flatArr = arr.flat(1);
10const flatArrAnyDepth = arr.flat(Infinity); 
11console.log(flatArr); // [1,2,1,2,2,3]