Snippet Javascript

With snippet Javascript, you can free your mind

1. Check Browser by Javascript

   Use navigator object for this and in that you can use userAgent property

   if (navigator.userAgent.indexOf('Firefox') != -1 && parseFloat(navigator.userAgent.substring(navigator.userAgent.indexOf('Firefox') + 8)) >= 10) {
     // Firefox version 10.0 and up
     // Allow
   } else if (navigator.userAgent.indexOf('Chrome') != -1 && parseFloat(navigator.userAgent.substring(navigator.userAgent.indexOf('Chrome') + 7).split(' ')[0]) >= 15) {
     // Chrome version 15 and up
     // Allow
   } else if (navigator.userAgent.indexOf('Safari') != -1 && navigator.userAgent.indexOf('Version') != -1 && parseFloat(navigator.userAgent.substring(navigator.userAgent.indexOf('Version') + 8).split(' ')[0]) >= 5){
     // Safari version 5 and up
     // Allow
   } else {
     // Block
   }
   

2. Select All Checkboxs Are Not Checked

   $("input:checkbox:unchecked").click();
   $("input:checkbox:unchecked").prop("checked", "checked");
   

3. Rounding Decimals

   The most common solutions for rounding to a decimal place is to either use Number.prototype.toFixed(), or multiply the float by some power of 10 in order to leverage Math.round(). Both of these work, except sometimes a decimal of 5 is rounded down instead of up.

   Number((1.005).toFixed(2)); // 1 instead of 1.01
   Math.round(1.005*100)/100; // 1 instead of 1.01
   

   A Better Solution

   The rounding problem can be avoided by using numbers represented in exponential notation:

   Number(Math.round(1.005+'e2')+'e-2'); // 1.01
   

   And to abstract that into something more usable:

   function round(value, decimals) {
     return Number(Math.round(value+'e'+decimals)+'e-'+decimals);
   }
   round(1.005, 2); // 1.01
   

4. Shuffle Array

   function shuffle(array) {
     var currentIndex = array.length, temporaryValue, randomIndex ;
     // While there remain elements to shuffle...
     while (0 !== currentIndex) {
       // Pick a remaining element...
       randomIndex = Math.floor(Math.random() * currentIndex);
       currentIndex -= 1;
       // And swap it with the current element.
       temporaryValue = array[currentIndex];
       array[currentIndex] = array[randomIndex];
       array[randomIndex] = temporaryValue;
     }
     return array;
   }
   

5. Check Scrollbar Visible

   (function($) {
     $.fn.hasScrollBar = function() {
       return this.get(0).scrollHeight > this.height();
     }
   })(jQuery);
   
   $(document).ready(function() {
     $('#div1').hasScrollBar(); // returns true if vertical scrollbar visible, false otherwise
   });
   

   Notes

   • If you have horizontal scrollbar that causes vertical scrollbar to appear, use clientHeight instead (this.get(0).clientHeight)
   • If you have padding, use innerHeight instead (this.innerHeight())