url.port

• <string>

获取和设置网址的端口部分。

端口值可以是数字，也可以是包含 0 到 65535（含）范围内的数字的字符串。 将值设置为给定 protocol 的 URL 对象的默认端口将导致 port 值成为空字符串 ('')。

端口值可以是空字符串，在这种情况下端口取决于协议/方案：

为端口分配值后，该值将首先使用 .toString() 转换为字符串。

如果该字符串无效但以数字开头，则将前导数字分配给 port。 如果数字在上述范围之外，则将其忽略。

const myURL = new URL('https://example.org:8888');
console.log(myURL.port);
// 打印 8888

// 默认端口自动转换为空字符串
//（HTTPS 协议的默认端口是 443）
myURL.port = '443';
console.log(myURL.port);
// 打印空字符串
console.log(myURL.href);
// 打印 https://example.org/

myURL.port = 1234;
console.log(myURL.port);
// 打印 1234
console.log(myURL.href);
// 打印 https://example.org:1234/

// 完全无效的端口字符串被忽略
myURL.port = 'abcd';
console.log(myURL.port);
// 打印 1234

// 前导数字被视为端口号
myURL.port = '5678abcd';
console.log(myURL.port);
// 打印 5678

// 非整数被截断
myURL.port = 1234.5678;
console.log(myURL.port);
// 打印 1234

// 未用科学计数法表示的超出范围的数字将被忽略。
myURL.port = 1e10; // 10000000000，将按如下所述进行范围检查
console.log(myURL.port);
// 打印 1234

包含小数点的数字，例如浮点数或科学记数法中的数字，也不例外。 小数点前的前导数字将被设置为网址的端口，假设它们是有效的：

myURL.port = 4.567e21;
console.log(myURL.port);
// 打印 4（因为它是字符串 '4.567e21' 中的前导数字）

• <string>

Gets and sets the port portion of the URL.

The port value may be a number or a string containing a number in the range 0 to 65535 (inclusive). Setting the value to the default port of the URL objects given protocol will result in the port value becoming the empty string ('').

The port value can be an empty string in which case the port depends on the protocol/scheme:

Upon assigning a value to the port, the value will first be converted to a string using .toString().

If that string is invalid but it begins with a number, the leading number is assigned to port. If the number lies outside the range denoted above, it is ignored.

const myURL = new URL('https://example.org:8888');
console.log(myURL.port);
// Prints 8888

// Default ports are automatically transformed to the empty string
// (HTTPS protocol's default port is 443)
myURL.port = '443';
console.log(myURL.port);
// Prints the empty string
console.log(myURL.href);
// Prints https://example.org/

myURL.port = 1234;
console.log(myURL.port);
// Prints 1234
console.log(myURL.href);
// Prints https://example.org:1234/

// Completely invalid port strings are ignored
myURL.port = 'abcd';
console.log(myURL.port);
// Prints 1234

// Leading numbers are treated as a port number
myURL.port = '5678abcd';
console.log(myURL.port);
// Prints 5678

// Non-integers are truncated
myURL.port = 1234.5678;
console.log(myURL.port);
// Prints 1234

// Out-of-range numbers which are not represented in scientific notation
// will be ignored.
myURL.port = 1e10; // 10000000000, will be range-checked as described below
console.log(myURL.port);
// Prints 1234

Numbers which contain a decimal point, such as floating-point numbers or numbers in scientific notation, are not an exception to this rule. Leading numbers up to the decimal point will be set as the URL's port, assuming they are valid:

myURL.port = 4.567e21;
console.log(myURL.port);
// Prints 4 (because it is the leading number in the string '4.567e21')