js日期格式化(字符串转日期<-->日期转字符串)

js字符串转日期型

/** year : /yyyy/ */
var _y4 = "([0-9]{4})";
/** year : /yy/ */
var _y2 = "([0-9]{2})";
/** index year */
var _yi = -1;
/** month : /MM/ */
var _M2 = "(0[1-9]|1[0-2])";
/** month : /M/ */
var _M1 = "([1-9]|1[0-2])";
/** index month */
var _Mi = -1;
/** day : /dd/ */
var _d2 = "(0[1-9]|[1-2][0-9]|30|31)";
/** day : /d/ */
var _d1 = "([1-9]|[1-2][0-9]|30|31)";
/** index day */
var _di = -1;
/** hour : /HH/ */
var _H2 = "([0-1][0-9]|20|21|22|23)";
/** hour : /H/ */
var _H1 = "([0-9]|1[0-9]|20|21|22|23)";
/** index hour */
var _Hi = -1;
/** minute : /mm/ */
var _m2 = "([0-5][0-9])";
/** minute : /m/ */
var _m1 = "([0-9]|[1-5][0-9])";
/** index minute */
var _mi = -1;
/** second : /ss/ */
var _s2 = "([0-5][0-9])";
/** second : /s/ */
var _s1 = "([0-9]|[1-5][0-9])";
/** index month */
var _si = -1;
var regexp;
function getDate(dateString, formatString) {
	if (validateDate(dateString, formatString)) {
		var now = new Date();
		var vals = regexp.exec(dateString);
		var index = validateIndex(formatString);
		var year = index[0] >= 0 ? vals[index[0] + 1] : now.getFullYear();
		var month = index[1] >= 0 ? (vals[index[1] + 1] - 1) : now.getMonth();
		var day = index[2] >= 0 ? vals[index[2] + 1] : now.getDate();
		var hour = index[3] >= 0 ? vals[index[3] + 1] : "";
		var minute = index[4] >= 0 ? vals[index[4] + 1] : "";
		var second = index[5] >= 0 ? vals[index[5] + 1] : "";
		var validate;
		if (hour == "") {
			validate = new Date(year, month, day);
		} else {
			validate = new Date(year, month, day, hour, minute, second);
		}
		if (validate.getDate() == day) {
			return validate;
		}
	}
	alert("wrong date");
}
function validateDate(dateString, formatString) {
	var dateString = trim(dateString);
	if (dateString == "") {
		return;
	}
	var reg = formatString;
	reg = reg.replace(/yyyy/, _y4);
	reg = reg.replace(/yy/, _y2);
	reg = reg.replace(/MM/, _M2);
	reg = reg.replace(/M/, _M1);
	reg = reg.replace(/dd/, _d2);
	reg = reg.replace(/d/, _d1);
	reg = reg.replace(/HH/, _H2);
	reg = reg.replace(/H/, _H1);
	reg = reg.replace(/mm/, _m2);
	reg = reg.replace(/m/, _m1);
	reg = reg.replace(/ss/, _s2);
	reg = reg.replace(/s/, _s1);
	reg = new RegExp("^" + reg + "$");
	regexp = reg;
	return reg.test(dateString);
}
function validateIndex(formatString) {
	var ia = new Array();
	var i = 0;
	_yi = formatString.search(/yyyy/);
	if (_yi < 0) {
		_yi = formatString.search(/yy/);
	}
	if (_yi >= 0) {
		ia[i] = _yi;
		i++;
	}
	_Mi = formatString.search(/MM/);
	if (_Mi < 0) {
		_Mi = formatString.search(/M/);
	}
	if (_Mi >= 0) {
		ia[i] = _Mi;
		i++;
	}
	_di = formatString.search(/dd/);
	if (_di < 0) {
		_di = formatString.search(/d/);
	}
	if (_di >= 0) {
		ia[i] = _di;
		i++;
	}
	_Hi = formatString.search(/HH/);
	if (_Hi < 0) {
		_Hi = formatString.search(/H/);
	}
	if (_Hi >= 0) {
		ia[i] = _Hi;
		i++;
	}
	_mi = formatString.search(/mm/);
	if (_mi < 0) {
		_mi = formatString.search(/m/);
	}
	if (_mi >= 0) {
		ia[i] = _mi;
		i++;
	}
	_si = formatString.search(/ss/);
	if (_si < 0) {
		_si = formatString.search(/s/);
	}
	if (_si >= 0) {
		ia[i] = _si;
		i++;
	}
	var ia2 = new Array(_yi, _Mi, _di, _Hi, _mi, _si);
	for (i = 0; i < ia.length - 1; i++) {
		for (j = 0; j < ia.length - 1 - i; j++) {
			if (ia[j] > ia[j + 1]) {
				temp = ia[j];
				ia[j] = ia[j + 1];
				ia[j + 1] = temp;
			}
		}
	}
	for (i = 0; i < ia.length; i++) {
		for (j = 0; j < ia2.length; j++) {
			if (ia[i] == ia2[j]) {
				ia2[j] = i;
			}
		}
	}
	return ia2;
}
function trim(str) {
	return str.replace(/(^\s*)|(\s*$)/g, "");
}

日期型格式化

Date.prototype.format = function(format)
{
	var o = {

		"M+" : this.getMonth()+1, //month
		"d+" : this.getDate(),//day
		"h+" : this.getHours(), //hour
		"m+" : this.getMinutes(), //minute
		"s+" : this.getSeconds(), //second
		"q+" : Math.floor((this.getMonth()+3)/3), //quarter
		"S" : this.getMilliseconds() //millisecond
	}

	if(/(y+)/.test(format)) 
		format = format.replace(RegExp.$1,(this.getFullYear()+"").substr(4 - RegExp.$1.length));
	for(var k in o)
		if(new RegExp("("+ k +")").test(format))
			format = format.replace(RegExp.$1,RegExp.$1.length==1 ? o[k] :("00"+ o[k]).substr((""+ o[k]).length));
	return format;
}