摘要：
let arr = [1, 2, [3, 4, 5, [6, 7, 8], 9], 10, [11, 12]]; flatten1 = arr => arr.flat(Infinity) flatten2 = arr => arr.toString().split(',').map(item => 阅读全文
摘要：
// 数组去重 let arr = ['a', 'b', 'b', 1, 1, 'true', true, true, NaN, NaN, 'NaN', undefined, undefined, null, null]; // 1. 集合 unique1 = arr => [...new Set( 阅读全文