JSDoc @param 标签
目录
同义词
-
JSDoc @arg 标签 -
JSDoc @argument 标签
概述
@param标签提供了对某个函数的参数的各项说明，包括参数名、参数数据类型、描述等。
@param标签要求您指定要描述参数的名称。您还可以包含参数的数据类型，使用大括号括起来，和参数的描述。
参数类型可以是一个内置的JavaScript类型，如string或Object，或是你代码中另一个标识符的JSDoc
namepath（名称路径）。如果你已经在这namepath（名称路径）上为标识符添加了描述，JSDoc会自动链接到该标识符的文档。您还可以使用type的表达式来表示，例如，该参数不能为空或可以接受任何类型;详见@type 标签文档。
如果您提供的描述，在描述之前插入一个连字符，可以使JSDoc注释更具可读性。请务必在连字符后加一个空格。
示例
名称, 类型, 和说明
下面的示例演示如何在 @param标签中包含名称，类型，和说明。
/**
* @param somebody
*/
function sayHello(somebody) {
alert('Hello ' + somebody);
}/**
* @param {string} somebody
*/
function sayHello(somebody) {
alert('Hello ' + somebody);
}/**
* @param {string} somebody Somebody's name.
*/
function sayHello(somebody) {
alert('Hello ' + somebody);
}You can add a hyphen before the description to make it more readable. Be sure to include a space before and after the hyphen.
/**
* @param {string} somebody - Somebody's name.
*/
function sayHello(somebody) {
alert('Hello ' + somebody);
}有属性的参数
如果参数是一个对象，有特定的属性，您可以通过@param标签提供额外的属性。例如，假如employee参数有name和department属性，您可以按以下方式描述:
/**
* Assign the project to an employee.
* @param {Object} employee - The employee who is responsible for the project.
* @param {string} employee.name - The name of the employee.
* @param {string} employee.department - The employee's department.
*/
Project.prototype.assign = function(employee) {
// ...
};If a parameter is destructured without an explicit name, you can give the object an appropriate one and document its properties.
/**
* Assign the project to an employee.
* @param {Object} employee - The employee who is responsible for the project.
* @param {string} employee.name - The name of the employee.
* @param {string} employee.department - The employee's department.
*/
Project.prototype.assign = function({ name, department }) {
// ...
};You can also combine this syntax with JSDoc's syntax for array parameters. For example, if multiple employees can be assigned to a project:
/**
* Assign the project to a list of employees.
* @param {Object[]} employees - The employees who are responsible for the project.
* @param {string} employees[].name - The name of an employee.
* @param {string} employees[].department - The employee's department.
*/
Project.prototype.assign = function(employees) {
// ...
};可选参数和默认值
下面的例子说明如何描述一个参数是可选的，并且具有默认值。
/**
* @param {string} [somebody] - Somebody's name.
*/
function sayHello(somebody) {
if (!somebody) {
somebody = 'John Doe';
}
alert('Hello ' + somebody);
}/**
* @param {string=} somebody - Somebody's name.
*/
function sayHello(somebody) {
if (!somebody) {
somebody = 'John Doe';
}
alert('Hello ' + somebody);
}/**
* @param {string} [somebody=John Doe] - Somebody's name.
*/
function sayHello(somebody) {
if (!somebody) {
somebody = 'John Doe';
}
alert('Hello ' + somebody);
}多少类型参数和可重复使用的参数
下面的例子演示了如何使用类型的表达式来表示一个参数可以接受多种类型（或任何类型），还有一个参数可以被多次使用。有关JSDoc支持的类型表达式细节请参阅@type 标签文档。
/**
* @param {(string|string[])} [somebody=John Doe] - Somebody's name, or an array of names.
*/
function sayHello(somebody) {
if (!somebody) {
somebody = 'John Doe';
} else if (Array.isArray(somebody)) {
somebody = somebody.join(', ');
}
alert('Hello ' + somebody);
}/**
* @param {*} somebody - Whatever you want.
*/
function sayHello(somebody) {
console.log('Hello ' + JSON.stringify(somebody));
}/**
* Returns the sum of all numbers passed to the function.
* @param {...number} num - A positive or negative number.
*/
function sum(num) {
var i = 0, n = arguments.length, t = 0;
for (; i < n; i++) {
t += arguments[i];
}
return t;
}回调函数
如果参数接受一个回调函数，您可以使用@callback标签来定义一个回调类型，然后回调类型包含到@param标签中。
/**
* This callback type is called `requestCallback` and is displayed as a global symbol.
*
* @callback requestCallback
* @param {number} responseCode
* @param {string} responseMessage
*/
/**
* Does something asynchronously and executes the callback on completion.
* @param {requestCallback} cb - The callback that handles the response.
*/
function doSomethingAsynchronously(cb) {
// code
};