var sum = 0;
for(var i = 1; i <= 5; i++){
  sum+=i;
}
console.log(sum/5);

var a = "1";
var b = 2;

console.log(a+b);

var _a = 1;
var _b = 2;

console.log(_a+_b);

console.log(parseFloat("23FF2"));