How To Tell If An Object Has A Given Prototype?

How can one detect if a given browser has the searchParams prototype for URL? https://developer.mozilla.org/en-US/docs/Web/API/URL/searchParams states that Chrome and FF do but Ed

Solution 1:

In supporting browsers, there will be an URLSearchParams constructor available on global object, so like any other global Constructor,

'URLSearchParams' in window

or

typeof window.URLSearchParams === 'function'

and alike will do.

const support = typeof window.URLSearchParams === 'function';
console.log('supports URLSearchParams API:', support);

var url = new URL('https://stackoverflow.com/questions/47824782/how-to-tell-if-an-object-has-a-given-prototype?support="true"');
if(support){
    console.log(url.searchParams.get('support'));
}

Solution 2:

You may want to add more to the Constructor I created, but it's like:

/* just for testing */ URL = undefined;
if(typeof URL === 'undefined'){
  URL = function(url){
    function sp(){
      var s = url.replace(/^.+?/, '').split('&'), o = {};
      for(var i=0,p,l=s.length; i<l; i++){
        p = s[i].split('='); o[p[0]] = p[1];
      }
      this.get = function(param){
        if(typeof o[param] === 'undefined'){
          return false;
        }
        return o[param];
      }
    }
    this.searchParams = new sp;
  }
}
var url = new URL('http://subdomain.domain.org/somefolder/deeperfolder?param1=value1&param2=value2&param3=value3&test=cool');
var params = url.searchParams;
console.log(params.get('nope'));
console.log(params.get('param2'));
console.log(params.get('test'));