New Parameter Functionality in JS

1. New Parameter Functionality
   
   Rest Params
   
   function testParams( i , ...j){
   var total = 0;
   j.forEach( function(value, index) { total += value; });
   return Math.pow(total,i);
   }
   testParams(2,1,2,3,4)
   100
   
   Rest Params with Arrow Functions
   function testParams( i , ...j){
   var total = 0;
   j.forEach( value => total += value);
   return Math.pow(total,i);
   
   }
   testParams(2,1,2,3,4)
   100
   
   default Params
   
   function testDefault(i, power =2){
   return Math.pow(i,power );
   }
   
   testDefault(10)
   100
   testDefault(10,3)
   1000