Web tricks - Some hot cookies?

Cookies are a way to store information on the user's computer. We can use them for a lot of different things: store the language, the graphical theme, login information (beware of security issues though), etc...
Here are a set of functions to manipulate those cookies through JavaScript.

Get

/**
 * Function to get a JavaScript cookie.
 * 
 * @see http://www.w3schools.com/js/js_cookies.asp
 * 
 * @param cName Name of the cookie to get.
 * @returns the value of the cookie, null if not found.
 */
function getCookie(cName) {
	var i, n, name, value, cookies = document.cookie.split(";");
	for (i = 0, n = cookies.length ; i < n ; i++) {
		name = cookies[i].substr(0, cookies[i].indexOf("="));
		name = name.replace(/^\s+|\s+$/g, "");
		if (name == cName) {
			value = cookies[i].substr(cookies[i].indexOf("=") + 1);
			return decodeURIComponent(value);
		}
	}
	return null;
}

Set

/**
 * Function to set a JavaScript cookie.
 * 
 * @see http://www.w3schools.com/js/js_cookies.asp
 * 
 * @param name Name of the cookie to set.
 * @param value Value of the cookie.
 * @param exDays (Optional) Days before expiration of the cookie.
 * @param domain (Optional) Domain on which the cookie is available.
 * @param path (Optional) Path on the server in which the cookie is available.
 * @param secure (Optional) Whether the cookie should be transmitted over a 
 * 		secure HTTPS.
 * @param httponly (Optional) Whether the cookie should be accessible through 
 * 		HTTP only (meaning it won't be accessible to client scripts).
 */
function setCookie(name, value, exDays, domain, path, secure, httponly) {
	// Name must be set
	if (name == null)
		return false;
	
	var exDate = new Date();
	exDate.setDate(exDate.getDate() + exDays);

	var value = encodeURIComponent(value);
	var expires_string = ((exDays == null) ? "" : "; expires=" + exDate.toUTCString());
	var domain_string = ((domain == null) ? "" : "; domain=" + domain);
	var path_string = ((path == null) ? "" : "; path=" + path);
	var secure_string = ((secure == null || !secure) ? "" : "; Secure");
	var httponly_string = ((secure == null || !secure) ? "" : "; Httponly");
	
	document.cookie = name + "=" + value
			+ expires_string + domain_string + path_string 
			+ secure_string + httponly_string;
	
	return true;
}

Unset

/**
 * Function to unset a JavaScript cookie.
 * 
 * @param name Name of the cookie to unset.
 */
function unsetCookie(name) {
	return setCookie(name, "", -1);
}

More information

• Dad ! Dad ! How do you cook cookies?
• ... Ask Wiki.

To get the cookies out of the oven: Fire Cookie.