1、数字数组转化为字符串数组
var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9];
arr.map(String); //结果: [\'1\', \'2\', \'3\', \'4\', \'5\', \'6\', \'7\', \'8\', \'9\']
2、字符串数组转化为数字数组
var a = [\'1\', \'2\', \'3\', \'4\', \'5\', \'6\', \'7\', \'8\', \'9\']
a.map(Number); //结果:[1, 2, 3, 4, 5, 6, 7, 8, 9]