SOURCE

const testURL = 'https://www.youzan.com?name=coder&age=20&callback=https%3A%2F%2Fyouzan.com%3Fname%3Dtest&list[]=a&list[]=b&json=%7B%22str%22%3A%22abc%22,%22num%22%3A123%7D&illegal=C%9E5%H__a100373__b4';


 function parseQueryString(url) {
    const obj = {}
    const temp = url.split('?')[1].split('&')
    const result = temp.map(item=>{
        return {
            key: item.split('=')[0],
            value: item.split('=')[1]
        }
    })
    obj.name = decodeURIComponent(result.find(item=>item.key === 'name').value)

    obj.age = result.find(item=>item.key === 'age').value
    obj.callback = decodeURIComponent(result.find(item=>item.key === 'callback').value)
    obj.list = result.reduce((acc,val)=>{
        return acc.concat(val.key === 'list[]'?val.value:[])
    },[])
    obj.json = JSON.parse(decodeURIComponent(result.find(item=>item.key === 'json').value))
 }
 parseQueryString(testURL)