1
function jsonP({ url, params }) {
2
    return new Promise((resolve, reject) => {
3
        window.callback = function (data) {
4
            resolve(data)
5
            document.body.removeChild(script)
6
        }
7
        const arrs = []
8
        // 将参数对象转成键值对(key-value)形式
9
        for (let key in params) {
10
            arrs.push(`${key}=${params[key]}`)
11
        }
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13
        let script = document.createElement('script')
14
        script.src = `${url}?${arrs.join('&')}&cb=callback`
15
        document.body.appendChild(script)
16
    })
17
}

1
let express = require('express')
2
let app = express()
3
app.listen(8089)
4
app.get('/sayHello',(req,res) => {
5
    let {wd,cb} = req.query
6
    res.end(`${cb}('hello world')`)
7
})

1
jsonP({
2
    url: 'http://localhost:8089/sayHello',
3
    params: {
4
        wd:'hello you'
5
    }
6
}).then((res) => {
7
    console.log(res)
8
})