Question

我写了一个链表，当我使用多个赋值时，结果很奇怪。在python和javascript之间有什么不同？

示例python代码

class ListNode(object):
def __init__(self, x):
    self.val = x
    self.next = None

node=ListNode(0)
node=node.next=ListNode(10)
#expect node.next=ListNode(10) node=node.next
print(node ==node.next) # True why?

相同的逻辑JavaScript代码

function ListNode(val){
    this.val=val;
    this.next=null;
}
var node=new ListNode(0);
node=node.next=new ListNode(10)
console.log(node==node.next) //false

Answer 1

实际上，您重新分配{ request: { method: 'GET', url: '//some-route', header: {accept: '*/*' } }等于server { listen 80; listen [::]:80 default_server ipv6only=on; return 301 https://$host$request_uri; } server { listen 443; server_name myapi.com; ssl on; # Use certificate and key provided by Let's Encrypt: ssl_certificate /etc/letsencrypt/live/myapi.com/fullchain.pem; ssl_certificate_key /etc/letsencrypt/live/myapi.com/privkey.pem; ssl_session_timeout 5m; ssl_protocols TLSv1 TLSv1.1 TLSv1.2; ssl_prefer_server_ciphers on; ssl_ciphers 'EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH'; location /api { proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header X-NginX-Proxy true; proxy_pass http://localhost:3000/; proxy_ssl_session_reuse off; proxy_set_header Host $http_host; proxy_cache_bypass $http_upgrade; proxy_redirect off; } }，因此node始终为node.next，因为这两个变量指向同一个对象。

Answer 2

在Python中，评估的顺序相反。因此：

node = node.next = ListNode(10)

与此相同：

node = ListNode(10)
node.next = node

因此，您必须在最后一次分配之前颠倒元素的顺序：

node.next = node = ListNode(10)
# same as:
node.next = ListNode(10)
node = node.next

Answer 3

我不确定你要用这条线完成什么：

node = node.next = ListNode(10)

如果您这样做：

node.next = ListNode(10)

您将获得所需的结果

in [1]: node=ListNode(0)

In [2]: node.val
Out[2]: 0

In [3]: node.next = ListNode(10)

In [4]: node.val
Out[4]: 0

In [5]: node.next.val
Out[5]: 10

In [6]: node == node.next
Out[6]: False

Answer 4

从右到左评估分配操作：

node.next = ListNode(10)
node = node.next

python assign（=）运算符是如何工作的

4 个答案: