如何在JavaScript中创建和读取cookie的值?
当前回答
下面是前面提到的w3schools的例子。
function setCookie(cname, cvalue, exdays) {
var d = new Date();
d.setTime(d.getTime() + (exdays*24*60*60*1000));
var expires = "expires="+ d.toUTCString();
document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
}
function getCookie(cname) {
var name = cname + "=";
var decodedCookie = decodeURIComponent(document.cookie);
var ca = decodedCookie.split(';');
for(var i = 0; i <ca.length; i++) {
var c = ca[i];
while (c.charAt(0) == ' ') {
c = c.substring(1);
}
if (c.indexOf(name) == 0) {
return c.substring(name.length, c.length);
}
}
return "";
}
其他回答
简约且功能齐全的ES6方法:
const setCookie = (name, value, days = 7, path = '/') => {
const expires = new Date(Date.now() + days * 864e5).toUTCString()
document.cookie = name + '=' + encodeURIComponent(value) + '; expires=' + expires + '; path=' + path
}
const getCookie = (name) => {
return document.cookie.split('; ').reduce((r, v) => {
const parts = v.split('=')
return parts[0] === name ? decodeURIComponent(parts[1]) : r
}, '')
}
const deleteCookie = (name, path) => {
setCookie(name, '', -1, path)
}
我用这个物体。值是经过编码的,所以在从服务器端读写时必须考虑到这一点。
cookie = (function() {
/**
* Sets a cookie value. seconds parameter is optional
*/
var set = function(name, value, seconds) {
var expires = seconds ? '; expires=' + new Date(new Date().getTime() + seconds * 1000).toGMTString() : '';
document.cookie = name + '=' + encodeURIComponent(value) + expires + '; path=/';
};
var map = function() {
var map = {};
var kvs = document.cookie.split('; ');
for (var i = 0; i < kvs.length; i++) {
var kv = kvs[i].split('=');
map[kv[0]] = decodeURIComponent(kv[1]);
}
return map;
};
var get = function(name) {
return map()[name];
};
var remove = function(name) {
set(name, '', -1);
};
return {
set: set,
get: get,
remove: remove,
map: map
};
})();
通过类似sessionStorage和localStorage的接口:
const cookieStorage = {
getItem: (key) {
const cookies = document.cookie.split(';')
.map(cookie => cookie.split('='))
.reduce(
(accumulation, [key, value]) => ({...accumulation, [key.trim()]: value}),
{}
)
return cookies[key]
},
setItem: (key, value) {
document.cookie = `${key}=${value}`
},
}
它的用法cookieStorage。setItem(", ")和cookieStorage.getItem(")。
下面是前面提到的w3schools的例子。
function setCookie(cname, cvalue, exdays) {
var d = new Date();
d.setTime(d.getTime() + (exdays*24*60*60*1000));
var expires = "expires="+ d.toUTCString();
document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
}
function getCookie(cname) {
var name = cname + "=";
var decodedCookie = decodeURIComponent(document.cookie);
var ca = decodedCookie.split(';');
for(var i = 0; i <ca.length; i++) {
var c = ca[i];
while (c.charAt(0) == ' ') {
c = c.substring(1);
}
if (c.indexOf(name) == 0) {
return c.substring(name.length, c.length);
}
}
return "";
}
在ES6中读取cookie的简单方法。
function getCookies() {
var cookies = {};
for (let cookie of document.cookie.split('; ')) {
let [name, value] = cookie.split("=");
cookies[name] = decodeURIComponent(value);
}
console.dir(cookies);
}