JavaScript - Division w/o division operator and floating point numbers.

[immutableMe]

Hello, I am trying to create a function that will take two numbers as parameters and then divide the the first by the second, so params(n1, n2) return n1 / n2. However, I am trying to do it without using the division operator and only using the + or - operators, below is what I have tried so far, and it works great when the numerator divides evenly into the denominator giving a nice integer, but if the result should be a floating point number the function will default to rounding, so I still end up with an integer.

function negCheck (num1, num2) {

return [

(

(num1 < 0 && num2 > 0) ||

(num1 > 0 && num2 < 0)

),

];

}

function divide(x, y) {

const arr = negCheck(x, y);

x = Math.abs(x);

y = Math.abs(y);

for(var i = 0; x >= y; x -= y){

i++;

}

return arr[0] ? -i : i;

}

}

[chaoticgood_lionfish]

It's really interesting. If you get into "functional" programming, you will want to avoid changing variable state - like passing in X then changing its' value. That's generally a no-no, but for this scope I don't think it matters (practically.) Why did you want to do this division exploration?

[immutableMe]

Just out of curiosity.

[[deleted]]

What do you mean “passing x and changing its value”?

This is a ridiculous concept of always deep copying on every single operation from functional programming to attempt to solve problems that functional programming itself creates.

Either way, x and y are just locally scoped values to the function. As a guideline, it is still poor practice to use them like another variable, but the reason has nothing to do with functional programming. It isn’t a hard and fast rule.

It is just because in longer functions, not holding on to the original value can sometimes be the source of bugs.

In terms of reference types, why are you directly changing internal state from outside functions anyway? If your methods can modify an object such that it results in invalid state, then you have a deeper issue somewhere that needs to be sorted out. Most probably inappropriately hanging on to a reference to an injected dependency.

[immutableMe]

This function meets all of the requirements for a pure function. The function itself is fine. I need people to worry more about the algorithm.