Exchange value

<Script>
         // The first method 
        var A = 2 ;
         var B =. 3 ;
         var C = A;
        a = b;
        b = c;
        console.log(a);
        console.log(b);

        // second method 
        var A = 2 ;
         var B =. 3 ;
        a = a + b; //5
        b = a - b; //5-3
        a = a - b; //5-2
        console.log(a);
        console.log(b);
    </script>