js函数像php格式化函数date一样

/** 
 * 和PHP一样的时间戳格式化函数 
 * @param {string} format 格式 
 * @param {int} timestamp 要格式化的时间戳 默认为当前时间戳 
 * @return {string}   格式化的时间字符串 
 */
function formatDate(format, timestamp){ 
	var a, jsdate=((timestamp) ? new Date(timestamp*1000) : new Date()); 
	var pad = function(n, c){ 
		if((n = n + "").length < c){ 
			return new Array(++c - n.length).join("0") + n; 
		} else { 
			return n; 
		} 
	}; 
	var txt_weekdays = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"]; 
	var txt_ordin = {1:"st", 2:"nd", 3:"rd", 21:"st", 22:"nd", 23:"rd", 31:"st"}; 
	var txt_months = ["", "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"]; 
	var f = { 
		// Day 
		d: function(){return pad(f.j(), 2)}, 
		D: function(){return f.l().substr(0,3)}, 
		j: function(){return jsdate.getDate()}, 
		l: function(){return txt_weekdays[f.w()]}, 
		N: function(){return f.w() + 1}, 
		S: function(){return txt_ordin[f.j()] ? txt_ordin[f.j()] : 'th'}, 
		w: function(){return jsdate.getDay()}, 
		z: function(){return (jsdate - new Date(jsdate.getFullYear() + "/1/1")) / 864e5 >> 0}, 

		// Week 
		W: function(){ 
			var a = f.z(), b = 364 + f.L() - a; 
			var nd2, nd = (new Date(jsdate.getFullYear() + "/1/1").getDay() || 7) - 1; 
			if(b <= 2 && ((jsdate.getDay() || 7) - 1) <= 2 - b){ 
				return 1; 
			} else{ 
				if(a <= 2 && nd >= 4 && a >= (6 - nd)){ 
					nd2 = new Date(jsdate.getFullYear() - 1 + "/12/31"); 
					return date("W", Math.round(nd2.getTime()/1000)); 
				} else{ 
					return (1 + (nd <= 3 ? ((a + nd) / 7) : (a - (7 - nd)) / 7) >> 0); 
				} 
			} 
		}, 

		// Month 
		F: function(){return txt_months[f.n()]}, 
		m: function(){return pad(f.n(), 2)}, 
		M: function(){return f.F().substr(0,3)}, 
		n: function(){return jsdate.getMonth() + 1}, 
		t: function(){ 
			var n; 
			if( (n = jsdate.getMonth() + 1) == 2 ){ 
				return 28 + f.L(); 
			} else{ 
				if( n & 1 && n < 8 || !(n & 1) && n > 7 ){ 
				return 31; 
				} else{ 
				 return 30; 
				} 
			} 
		}, 

		// Year 
		L: function(){var y = f.Y();return (!(y & 3) && (y % 1e2 || !(y % 4e2))) ? 1 : 0}, 
		//o not supported yet 
		Y: function(){return jsdate.getFullYear()}, 
		y: function(){return (jsdate.getFullYear() + "").slice(2)}, 

		// Time 
		a: function(){return jsdate.getHours() > 11 ? "pm" : "am"}, 
		A: function(){return f.a().toUpperCase()}, 
		B: function(){ 
		// peter paul koch: 
		var off = (jsdate.getTimezoneOffset() + 60)*60; 
		var theSeconds = (jsdate.getHours() * 3600) + (jsdate.getMinutes() * 60) + jsdate.getSeconds() + off; 
		var beat = Math.floor(theSeconds/86.4); 
		if (beat > 1000) beat -= 1000; 
		if (beat < 0) beat += 1000; 
		if ((String(beat)).length == 1) beat = "00"+beat; 
		if ((String(beat)).length == 2) beat = "0"+beat; 
			return beat; 
		}, 
		g: function(){return jsdate.getHours() % 12 || 12}, 
		G: function(){return jsdate.getHours()}, 
		h: function(){return pad(f.g(), 2)}, 
		H: function(){return pad(jsdate.getHours(), 2)}, 
		i: function(){return pad(jsdate.getMinutes(), 2)}, 
		s: function(){return pad(jsdate.getSeconds(), 2)}, 
		//u not supported yet 

		// Timezone 
		//e not supported yet 
		//I not supported yet 
		O: function(){ 
			var t = pad(Math.abs(jsdate.getTimezoneOffset()/60*100), 4); 
			if (jsdate.getTimezoneOffset() > 0) t = "-" + t; else t = "+" + t; 
			return t; 
		}, 
		P: function(){var O = f.O();return (O.substr(0, 3) + ":" + O.substr(3, 2))}, 
		//T not supported yet 
		//Z not supported yet 

		// Full Date/Time 
		c: function(){return f.Y() + "-" + f.m() + "-" + f.d() + "T" + f.h() + ":" + f.i() + ":" + f.s() + f.P()}, 
		//r not supported yet 
		U: function(){return Math.round(jsdate.getTime()/1000)} 
	}; 

	return format.replace(/([a-zA-Z])/g, function(t, s){ 
		if( t!=s ){ 
			// escaped 
			ret = s; 
		} else if( f[s] ){ 
			// a date function exists 
			ret = f[s](); 
		} else{ 
			// nothing special 
			ret = s; 
		} 
		return ret; 
	}); 
}

用法：formatDate("Y-m-d H:i:s",'1263081600');

输出：2010-01-10 08:00:00