Answer 1

var arrOne =["A1", "A2", "B1", "B2", "C1", "C2", "D1", "D2"]； var arrTwo = ['A', 'B', 'C', 'D'];

for (let i = 0; i < arrTwo.length; i++) { let re = new RegExp(arrTwo[i], 'g'); for (let x = arrOne.length; x > 0; x--) { if(re.test(arrOne[x])){ arrOne.splice(x+1,0,arrTwo[i]) } } } console.log(arrOne);

这样是否可以呢？

我想请教下，为啥test加了g全局后，A2匹配不到

Answer 2

str.split("").reverse().reduce((prev, cur, index) => (index + 1) % 3 == 0 ? '.' + cur + prev : cur + prev)

有点问题
'100000000'.split("").reverse().reduce((prev, cur, index) => (index + 1) % 3 == 0 ? '.' + cur + prev : cur + prev)
=> //".100.000.000"

Answer 3

哈哈，还在疑惑呢，题目是啥意思，原来是markdown中两个~构成了删除线，要用~来写~呢