这是递归的一种替代方法，并且应接受任何深度级别，以避免堆栈溢出。
var array = [[0, 1], [2, 3], [4, 5, [6, 7, [8, [9, 10]]]]];console.log(flatten(array), array); // does not mutate arrayconsole.log(flatten(array, true), array); // array is now empty// This is done in a linear time O(n) without recursion// memory complexity is O(1) or O(n) if mutable param is set to falsefunction flatten(array, mutable) { var toString = Object.prototype.toString; var arrayTypeStr = '[object Array]'; var result = []; var nodes = (mutable && array) || array.slice(); var node; if (!array.length) { return result; } node = nodes.pop(); do { if (toString.call(node) === arrayTypeStr) { nodes.push.apply(nodes, node); } else { result.push(node); } } while (nodes.length && (node = nodes.pop()) !== undefined); result.reverse(); // we reverse result to restore the original order return result;}
