Flatten Array Golf
console.log([100, 200, [2], [3, 4, [2, 3, [5]], 100]]+'')
// outputs: "100,200,2,3,4,2,3,5,100"
Coercing a multidimensional array to a string flattens it and joins it with commas
console.log([100, 200, [2], [3, 4, [2, 3, [5]], 100]]+'')
// outputs: "100,200,2,3,4,2,3,5,100"
Coercing a multidimensional array to a string flattens it and joins it with commas