Plain Javascript Equivalent of jQuery.param()

Question

jQuery.param() takes an array of key-value pairs, and turns it into a string you can use as a query string in HTML requests. For example,

a = {
      userid:1,
         


        

Answer 1

ES6 version that allows to convert nested objects and arrays just use like encodeURI(getUrlString({a: 1, b: [true, 12.3, "string"]})).

getUrlString (params, keys = [], isArray = false) {
  const p = Object.keys(params).map(key => {
    let val = params[key]

    if ("[object Object]" === Object.prototype.toString.call(val) || Array.isArray(val)) {
      if (Array.isArray(params)) {
        keys.push("")
      } else {
        keys.push(key)
      }
      return getUrlString(val, keys, Array.isArray(val))
    } else {
      let tKey = key

      if (keys.length > 0) {
        const tKeys = isArray ? keys : [...keys, key]
        tKey = tKeys.reduce((str, k) => { return "" === str ? k : `${str}[${k}]` }, "")
      }
      if (isArray) {
        return `${ tKey }[]=${ val }`
      } else {
        return `${ tKey }=${ val }`
      }

    }
  }).join('&')

  keys.pop()
  return p
}