What is the role of filter() method in JavaScript?

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JavaScript array filter() method creates a new array with all elements that pass the test implemented by the provided function.

The following are the parameters −

  • callback − Function to test each element of the array.

  • thisObject − Object to use as this when executing callback.

You can try to run the following code to learn how to work with filter() method in JavaScript −

Example

Live Demo

<html>
   <head>
      <title>JavaScript Array filter Method</title>
   </head>
   
   <body>
      <script>
         if (!Array.prototype.filter) {
            Array.prototype.filter = function(fun /*, thisp*/) {
               var len = this.length;

               if (typeof fun != "function")
               throw new TypeError();

               var res = new Array();
               var thisp = arguments[1];

               for (var i = 0; i < len; i++) {
                  if (i in this) {
                  var val = this[i]; // in case fun mutates this
                  if (fun.call(thisp, val, i, this))
                  res.push(val);
                  }
               }
               return res;
            };
         }
         function isBigEnough(element, index, array) {
            return (element >= 10);
         }

         var filtered = [12, 5, 8, 130, 44].filter(isBigEnough);
         document.write("Filtered Value : " + filtered );
      </script>
   </body>
   
</html>
raja
Published on 26-Feb-2018 12:28:51
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