let queryString = 'a=1&b=2&c=3'
URL参数转对象
//let o = Object.fromEntries(new URLSearchParams(queryString).entries())
let o = Object.fromEntries(new URLSearchParams(queryString))
// {a: '1', b: '2', c: '3'}
对象转URL参数
let s = new URLSearchParams(o).toString()
//'a=1&b=2&c=3'