急求两个正则表达式

Question

1.日期 格式为 year-month-day
能匹配2009-05-04 也能匹配09-5-42.能匹配整数或小数且小数的位数最多为4

Answer 1

1.
\d{4}-\d{2}-\d{2}|\d{2}-[^0]{1,2}-[^0]{1,2}2.
\d+?\.\d{1,4}|-?\d+

Answer 2

(?:[12]\d)?\d\d-(?:0?[1-9]|1[0-2])-(?:0?[1-9]|[12]\d|3[01])[1-9]\d*|0(?.\d{0,4})+
这样？

Answer 3

不需要很严格的话^\d\d(?:\d\d)?\-\d\d?\-\d\d?$^\-?\d+(?:\.\d{1,4})?$

Answer 4

var reg1 = /^(?:\d{4}|\d{2})-(?:(?:0?[1-9])|(?:1[0-2]))-(?:(?:0?[1-9])|(?:[12]\d)|(?:3[01]))$/;
var reg2 = /^[+-]?\d+(.\d{1,4})?$/;