考虑示例代码:
function makeRequest(endpoint, form = {}, qs = {}, callback) {
const exampleObject = {
endpoint,
form,
qs,
};
callback(exampleObject);
}
makeRequest('/example', { foo: 'string' }, { bar: 'string' }, (exampleObject) => {
console.log(exampleObject);
});
在上面的示例中,以下对象将记录在控制台上:
{ endpoint: '/example',
form: { foo: 'string' },
qs: { bar: 'string' } }
如何在中使用默认值makeRequest
并仍然使用回调?例如,以下失败:
makeRequest('/example', (exampleObject) => {
console.log(exampleObject);
});
输出:
/Users/daniel/example.js:13
callback(exampleObject);
^
TypeError: callback is not a function
at makeRequest (example.js:7:3)
at Object.<anonymous> (example.js:10:1)
at Module._compile (module.js:409:26)
at loader (/usr/local/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:148:5)
at Object.require.extensions.(anonymous function) [as .js] (/usr/local/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:158:7)
at Module.load (module.js:343:32)
at Function.Module._load (module.js:300:12)
at Function.Module.runMain (module.js:441:10)
at /usr/local/lib/node_modules/babel-cli/lib/_babel-node.js:160:24
at Object.<anonymous> (/usr/local/lib/node_modules/babel-cli/lib/_babel-node.js:161:7)
考虑到我只发送一个参数,这是有道理的。我想知道如何makeRequest
在利用默认参数的同时调用并仍然获得回调。如果存在回调,我是否总是必须传递三个参数?还有其他解决方法,因此我可以选择仅在需要时使用第二个和第三个参数,并且始终进入exampleObject
回调函数?
如何进行销毁?
function makeRequest({ endpoint, form = {}, qs = {}, callback = () => {} }) {
const exampleObject = {
endpoint,
form,
qs,
};
callback(exampleObject);
}
makeRequest({
endpoint: '/example',
callback: (x) => console.log(x)
});
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