function flat(list) { const result = []; list.forEach(item => { if (Array.isArray(item)) { result.push(...flat(item)); } else { result.push(item); } }) return result; } const list = [3, [5, 2], [1, 1, [7],5]]; // 方案一: console.log(list.toString().split(',').map(item => +item)); // 方案二: console.log(flat(list));