---
title: "Is Date"
type: "forum-thread"
url: "https://www.webforum.nu/amne/javascript/177424-is-date"
topic: "JavaScript"
topic_url: "https://www.webforum.nu/amne/javascript"
author: "firstchoice"
published: "2009-03-13T13:41:36.000Z"
updated: "2009-03-17T10:20:40.000Z"
replies: 1
views: 409
page: 1
pages: 1
language: "sv-SE"
site: "webForum — webforum.nu"
rights: "Upphovsrätten till varje inlägg tillhör dess författare."
attribution: "Citera som: webForum, https://www.webforum.nu/amne/javascript/177424-is-date"
---

# Is Date

## #1 — firstchoice, 2009-03-13T13:41Z

behöver en koll om de har skrivit in ett giltigt datum enligt yyyy-mm-dd

har idag denna koden

```
function addOption(optText,frm_name,lstBox_name)
{	
	var optValue = document.forms[frm_name].elements[optText].value;

	if (optValue != '')
	{
		var Box = document.forms[frm_name].elements[lstBox_name];
		var i = 0;
		var test = true;
		while(i<Box.options.length)
	{
	if (Box.options[i].value == optValue) {test = false; break;}
		i++;
		}
	if (test)
	{
		var newOption = new Option(optValue,optValue);
		var Box = document.forms[frm_name].elements[lstBox_name];
		Box.options[Box.options.length] = newOption;
	}
	else
	{
		alert('You have already choice that date!');
	}
	}
	else
	{
		alert('You have to select a date!');
	}
		return false;
}
```

vill göra en koll på variablen "optValue"

Permalänk: https://www.webforum.nu/p/177424

## #2 — Jojoxx, 2009-03-17T10:20Z

```
[red]String.prototype.isValidDate = function(){
	if(!this.match(/^(\d{4})\-(\d{2})\-(\d{2})$/)){ return false; }
	return (RegExp.$3<=new Date(RegExp.$1,RegExp.$2,0).getDate()&&RegExp.$3>0&&RegExp.$2<13&&RegExp.$2>0);
}[/red]
function addOption(optText,frm_name,lstBox_name)
{	
	var optValue = document.forms[frm_name].elements[optText].value;

	if (optValue != '')
	{
		[red]if(!optValue.isValidDate()){ alert('Date is invalid'); return false; }[/red]
		var Box = document.forms[frm_name].elements[lstBox_name];
		var i = 0;
		var test = true;
		while(i<Box.options.length)
	{
	if (Box.options[i].value == optValue) {test = false; break;}
		i++;
		}
	if (test)
	{
		var newOption = new Option(optValue,optValue);
		var Box = document.forms[frm_name].elements[lstBox_name];
		Box.options[Box.options.length] = newOption;
	}
	else
	{
		alert('You have already choice that date!');
	}
	}
	else
	{
		alert('You have to select a date!');
	}
		return false;
}
```

Tillagd kod markerad.

Permalänk: https://www.webforum.nu/p/2175564

---

Tråden på webben: https://www.webforum.nu/amne/javascript/177424-is-date