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

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 −


Live Demo

      <title>JavaScript Array filter Method</title>
         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))
               return res;
         function isBigEnough(element, index, array) {
            return (element >= 10);

         var filtered = [12, 5, 8, 130, 44].filter(isBigEnough);
         document.write("Filtered Value : " + filtered );

Updated on: 30-Jul-2019


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