<element onresize = "fun()">
  object.onresize = function() { myScript };
  object.addEventListener("resize", myScript);
  <!DOCTYPE html>
 <html>
 <head>
 <script>
 var i = 0;
 function fun() {
 var res = "Width = " + window.outerWidth + "<br>" + "Height = " + window.outerHeight;
 document.getElementById("para").innerHTML = res;
 var res1 = i += 1;
 document.getElementById("s1").innerHTML = res1;
 }
 </script>
 </head>
 <body onresize = "fun()">
 <h3> This is an example of using onresize attribute. </h3>
 <p> Try to resize the browser's window to see the effect. </p>
 <p id = "para"> </p>
 <p> You have resized the window <span id = "s1"> 0 </span> times.</p>
 </body>
 </html>
  
 
 
 
 <!DOCTYPE html>
 <html>
 <head>
 </head>
 <body>
 <h3> This is an example of using JavaScript's onresize event. </h3>
 <p> Try to resize the browser's window to see the effect. </p>
 <p id = "para"> </p>
 <p> You have resized the window <span id = "s1"> 0 </span> times.</p>
 <script>
 document.getElementsByTagName("BODY")[0].onresize = function() {fun()};
 var i = 0;
 function fun() {
 var res = "Width = " + window.outerWidth + "<br>" + "Height = " + window.outerHeight;
 document.getElementById("para").innerHTML = res;
 var res1 = i += 1;
 document.getElementById("s1").innerHTML = res1;
 }
 </script>
 </body>
 </html>
  
 
 
 
 <!DOCTYPE html>
 <html>
 <head>
 </head>
 <body>
 <h3> This is an example of using JavaScript's addEventListener() method. </h3>
 <p> Try to resize the browser's window to see the effect. </p>
 <p id = "para"> </p>
 <p> You have resized the window <span id = "s1"> 0 </span> times.</p>
 <script>
 window.addEventListener("resize", fun);
 var i = 0;
 function fun() {
 var res = "Width = " + window.outerWidth + "<br>" + "Height = " + window.outerHeight;
 document.getElementById("para").innerHTML = res;
 var res1 = i += 1;
 document.getElementById("s1").innerHTML = res1;
 }
 </script>
 </body>
 </html>
  
 
