A smarter approach would be to write a function that uses many conditional statements to return incremental values ​​based on different numerical ranges

Question

I'm trying to write a function that returns a specific value if the input is within a certain range of numbers.

Normally, I would write a series of if/else if statements to accomplish this task. However, I'm dealing with a large number of ranges, so writing out 30+ if/else if statements seems inefficient.

Suppose I have a minimum and maximum number for an overall range, and I want to split it into smaller ranges. For each range I want to return some values. Ideally, the return value for each range would be decremented by some fixed number.

To provide context, I'm trying to calculate a value based on mileage using something like this. For example, if the mileage is between 101-120 miles, the rate is equal to 80% of the mileage. The percentage decreases as mileage increases. Moreover, the value of the percentage decrease can be a fixed number (such as -0.05)

...
else if (m >= 101 && m <= 120) return 0.80
else if (m >= 121 && m <= 140) return 0.75
...

Since there is a pattern in the return value for each range, I think it can be done in a better way than writing a bunch of if/else statements, but I'm not sure exactly how. Any ideas?

Answer 1

Your example does not increment by 15; so, I'm assuming that's a typo.

I will use a function to solve it. For example:

(() => {

// 在你的例子中，你有 .95 -> .9 -> .85，因此这从1开始。
const STARTING_RETURN_VALUE = 1;

// if语句中的递增范围是15
const INCREMENT = 15;

// 这是每个间隔中返回值递减的值
const DECREASING_RETURN_VALUE = .05;

const getReturn = (x, increment, starting_return_value, decreasing_return_value) => {
     return starting_return_value - (Math.floor(x/increment)+1)*decreasing_return_value;
}

console.log(getReturn(29, INCREMENT, STARTING_RETURN_VALUE, DECREASING_RETURN_VALUE));

})();