如果你有一个url字符串，你想用一个参数来装饰，你可以试试这个在线程序:

urlstring += ( urlstring.match( /[\?]/g ) ? '&' : '?' ) + 'param=value';

这意味着什么?将是参数的前缀，但如果已经有?在urlstring中，than &将是前缀。

我也会建议做encodeURI(paramvariable)，如果你没有硬编码参数，但它是在一个paramvariable;或者里面有有趣的角色。

encodeURI函数的使用请参见javascript URL编码。

我添加我的解决方案，因为它支持相对url除了绝对url。在其他方面，它与顶部的答案相同，后者也使用Web API。

/**
 * updates a relative or absolute
 * by setting the search query with
 * the passed key and value.
 */
export const setQueryParam = (url, key, value) => {
  const dummyBaseUrl = 'https://dummy-base-url.com';
  const result = new URL(url, dummyBaseUrl);
  result.searchParams.set(key, value);
  return result.toString().replace(dummyBaseUrl, '');
};

还有人开玩笑说:

// some jest tests
describe('setQueryParams', () => {
  it('sets param on relative url with base path', () => {
    // act
    const actual = setQueryParam(
      '/', 'ref', 'some-value',
    );
    // assert
    expect(actual).toEqual('/?ref=some-value');
  });
  it('sets param on relative url with no path', () => {
    // act
    const actual = setQueryParam(
      '', 'ref', 'some-value',
    );
    // assert
    expect(actual).toEqual('/?ref=some-value');
  });
  it('sets param on relative url with some path', () => {
    // act
    const actual = setQueryParam(
      '/some-path', 'ref', 'some-value',
    );
    // assert
    expect(actual).toEqual('/some-path?ref=some-value');
  });
  it('overwrites existing param', () => {
    // act
    const actual = setQueryParam(
      '/?ref=prev-value', 'ref', 'some-value',
    );
    // assert
    expect(actual).toEqual('/?ref=some-value');
  });
  it('sets param while another param exists', () => {
    // act
    const actual = setQueryParam(
      '/?other-param=other-value', 'ref', 'some-value',
    );
    // assert
    expect(actual).toEqual('/?other-param=other-value&ref=some-value');
  });
  it('honors existing base url', () => {
    // act
    const actual = setQueryParam(
      'https://base.com', 'ref', 'some-value',
    );
    // assert
    expect(actual).toEqual('https://base.com/?ref=some-value');
  });
  it('honors existing base url with some path', () => {
    // act
    const actual = setQueryParam(
      'https://base.com/some-path', 'ref', 'some-value',
    );
    // assert
    expect(actual).toEqual('https://base.com/some-path?ref=some-value');
  });
});

试一试 正则表达式，如此之慢，因此:

var SetParamUrl = function(_k, _v) {// replace and add new parameters

    let arrParams = window.location.search !== '' ? decodeURIComponent(window.location.search.substr(1)).split('&').map(_v => _v.split('=')) : Array();
    let index = arrParams.findIndex((_v) => _v[0] === _k); 
    index = index !== -1 ? index : arrParams.length;
    _v === null ? arrParams = arrParams.filter((_v, _i) => _i != index) : arrParams[index] = [_k, _v];
    let _search = encodeURIComponent(arrParams.map(_v => _v.join('=')).join('&'));

    let newurl = window.location.protocol + "//" + window.location.host + window.location.pathname + (arrParams.length > 0 ? '?' +  _search : ''); 

    // window.location = newurl; //reload 

    if (history.pushState) { // without reload  
        window.history.pushState({path:newurl}, null, newurl);
    }

};

var GetParamUrl = function(_k) {// get parameter by key

    let sPageURL = decodeURIComponent(window.location.search.substr(1)),
        sURLVariables = sPageURL.split('&').map(_v => _v.split('='));
    let _result = sURLVariables.find(_v => _v[0] === _k);
    return _result[1];

};

例子:

        // https://some.com/some_path
        GetParamUrl('cat');//undefined
        SetParamUrl('cat', "strData");// https://some.com/some_path?cat=strData
        GetParamUrl('cat');//strData
        SetParamUrl('sotr', "strDataSort");// https://some.com/some_path?cat=strData&sotr=strDataSort
        GetParamUrl('sotr');//strDataSort
        SetParamUrl('cat', "strDataTwo");// https://some.com/some_path?cat=strDataTwo&sotr=strDataSort
        GetParamUrl('cat');//strDataTwo
        //remove param
        SetParamUrl('cat', null);// https://some.com/some_path?sotr=strDataSort

你需要适应的基本实现是这样的:

function insertParam(key, value) {
    key = encodeURIComponent(key);
    value = encodeURIComponent(value);

    // kvp looks like ['key1=value1', 'key2=value2', ...]
    var kvp = document.location.search.substr(1).split('&');
    let i=0;

    for(; i<kvp.length; i++){
        if (kvp[i].startsWith(key + '=')) {
            let pair = kvp[i].split('=');
            pair[1] = value;
            kvp[i] = pair.join('=');
            break;
        }
    }

    if(i >= kvp.length){
        kvp[kvp.length] = [key,value].join('=');
    }

    // can return this or...
    let params = kvp.join('&');

    // reload page with new params
    document.location.search = params;
}

这大约是正则表达式或基于搜索的解决方案的两倍，但这完全取决于查询字符串的长度和任何匹配的索引

为了完成起见，我以慢速regex方法为基准(大约慢了150%)

function insertParam2(key,value)
{
    key = encodeURIComponent(key); value = encodeURIComponent(value);

    var s = document.location.search;
    var kvp = key+"="+value;

    var r = new RegExp("(&|\\?)"+key+"=[^\&]*");

    s = s.replace(r,"$1"+kvp);

    if(!RegExp.$1) {s += (s.length>0 ? '&' : '?') + kvp;};

    //again, do what you will here
    document.location.search = s;
}

我喜欢穆罕穆德·法提赫·耶尔达兹的回答，即使他没有回答整个问题。

在他回答的同一行中，我使用了这样的代码:

“它不控制参数的存在，也不改变现有的值。它把你的参数加到最后"

  /** add a parameter at the end of the URL. Manage '?'/'&', but not the existing parameters.
   *  does escape the value (but not the key)
   */
  function addParameterToURL(_url,_key,_value){
      var param = _key+'='+escape(_value);

      var sep = '&';
      if (_url.indexOf('?') < 0) {
        sep = '?';
      } else {
        var lastChar=_url.slice(-1);
        if (lastChar == '&') sep='';
        if (lastChar == '?') sep='';
      }
      _url += sep + param;

      return _url;
  }

测试者:

  /*
  function addParameterToURL_TESTER_sub(_url,key,value){
    //log(_url);
    log(addParameterToURL(_url,key,value));
  }

  function addParameterToURL_TESTER(){
    log('-------------------');
    var _url ='www.google.com';
    addParameterToURL_TESTER_sub(_url,'key','value');
    addParameterToURL_TESTER_sub(_url,'key','Text Value');
    _url ='www.google.com?';
    addParameterToURL_TESTER_sub(_url,'key','value');
    _url ='www.google.com?A=B';
    addParameterToURL_TESTER_sub(_url,'key','value');
    _url ='www.google.com?A=B&';
    addParameterToURL_TESTER_sub(_url,'key','value');
    _url ='www.google.com?A=1&B=2';
    addParameterToURL_TESTER_sub(_url,'key','value');

  }//*/

以下功能将帮助您添加，更新和删除参数或从URL。

/ / example1and

var myURL = '/search';

myURL = updateUrl(myURL,'location','california');
console.log('added location...' + myURL);
//added location.../search?location=california

myURL = updateUrl(myURL,'location','new york');
console.log('updated location...' + myURL);
//updated location.../search?location=new%20york

myURL = updateUrl(myURL,'location');
console.log('removed location...' + myURL);
//removed location.../search

/ / example2

var myURL = '/search?category=mobile';

myURL = updateUrl(myURL,'location','california');
console.log('added location...' + myURL);
//added location.../search?category=mobile&location=california

myURL = updateUrl(myURL,'location','new york');
console.log('updated location...' + myURL);
//updated location.../search?category=mobile&location=new%20york

myURL = updateUrl(myURL,'location');
console.log('removed location...' + myURL);
//removed location.../search?category=mobile

/ /青年们

var myURL = '/search?location=texas';

myURL = updateUrl(myURL,'location','california');
console.log('added location...' + myURL);
//added location.../search?location=california

myURL = updateUrl(myURL,'location','new york');
console.log('updated location...' + myURL);
//updated location.../search?location=new%20york

myURL = updateUrl(myURL,'location');
console.log('removed location...' + myURL);
//removed location.../search

/ / example4

var myURL = '/search?category=mobile&location=texas';

myURL = updateUrl(myURL,'location','california');
console.log('added location...' + myURL);
//added location.../search?category=mobile&location=california

myURL = updateUrl(myURL,'location','new york');
console.log('updated location...' + myURL);
//updated location.../search?category=mobile&location=new%20york

myURL = updateUrl(myURL,'location');
console.log('removed location...' + myURL);
//removed location.../search?category=mobile

/ / example5

var myURL = 'https://example.com/search?location=texas#fragment';

myURL = updateUrl(myURL,'location','california');
console.log('added location...' + myURL);
//added location.../search?location=california#fragment

myURL = updateUrl(myURL,'location','new york');
console.log('updated location...' + myURL);
//updated location.../search?location=new%20york#fragment

myURL = updateUrl(myURL,'location');
console.log('removed location...' + myURL);
//removed location.../search#fragment

这是函数。

function updateUrl(url,key,value){
      if(value!==undefined){
        value = encodeURI(value);
      }
      var hashIndex = url.indexOf("#")|0;
      if (hashIndex === -1) hashIndex = url.length|0;
      var urls = url.substring(0, hashIndex).split('?');
      var baseUrl = urls[0];
      var parameters = '';
      var outPara = {};
      if(urls.length>1){
          parameters = urls[1];
      }
      if(parameters!==''){
        parameters = parameters.split('&');
        for(k in parameters){
          var keyVal = parameters[k];
          keyVal = keyVal.split('=');
          var ekey = keyVal[0];
          var evalue = '';
          if(keyVal.length>1){
              evalue = keyVal[1];
          }
          outPara[ekey] = evalue;
        }
      }

      if(value!==undefined){
        outPara[key] = value;
      }else{
        delete outPara[key];
      }
      parameters = [];
      for(var k in outPara){
        parameters.push(k + '=' + outPara[k]);
      }

      var finalUrl = baseUrl;

      if(parameters.length>0){
        finalUrl += '?' + parameters.join('&'); 
      }

      return finalUrl + url.substring(hashIndex); 
  }