javascript (200-200)/100 = 9009

Question

So I am working on a formula with javascript. and this is the formula. The data for the tank variables is gathered from inputfields.

y = ((tank1 + tank2 + (tank 3 /25)) - (tank4 + tank4))/100;
alert(y);

so for tank1 = 100 tank2 = 100 and tank3 = 0 tank4 = 100 and tank5 =100

according to javascript the answer to this is 9009 while it is supposed to be 0.

for tank1 = 90 tank2 = 90 tank3 = 0 tank4 = 90 and tank5 = 90 answer = 818.6

I tried changing the divisions to multiplications /25 to 0.04 and /100 to 0.01 but the results were the same. I also tried renaming the tanks in case they were referring to the wrong tanks. I have also tried alerting the tanks and they gave the right inserted numbers back. I am running Jquery.

Does anyone Know what is causing this?

Answer 1

Just use parseInt(tankX) for every tank variable and it will work as expected.

This is because your values come from input fields as strings not integers.

Reference: parseInt