Create value between two numbers by percentage-CodePudding

I have 2 arrays: [-26, -5] [-5.3, 2.3], and a percentage value from 0 to 100 that changes on scroll.

I need a function that generates a number by percentage between two numbers, where percentage 0 is the first value from the array, and where 100 percent is the second value. 50% is exactly in the middle of the two numbers. After receiving a number, reduce it to hundredths.

For example:

const result1 = someMagick(50%, [-26, -5]);
const result2 = someMagick(100%, [-26, -5]);

console.log(result1, result2)
// -16, -26

I don’t have any thoughts how to do it, please help

CodePudding user response：

I don't know why your min and max are reversed, but here you go:

const result1 = someMagick(0.5, [-26, -5]);
const result2 = someMagick(1, [-26, -5]);

console.log(result1, result2)

function someMagick(percent, [max, min]) {
  return (max - min) * percent   min
}

CodePudding user response：

function someMagick(percentage, numbers) {
  // Convert percentage value to decimal
  const decimalPercentage = percentage / 100;

  // Calculate range between numbers
  const range = numbers[1] - numbers[0];

  // Calculate result by adding first number in array to the product of the percentage value and the range
  const result = numbers[0]   (decimalPercentage * range);

  // Return result rounded to the nearest hundredth
  return Math.round(result * 100) / 100;
}

// Example usage
const result1 = someMagick(50, [-26, -5]);
const result2 = someMagick(100, [-26, -5]);

console.log(result1, result2);
// -16, -26

You can then use this function to generate a number by percentage between two numbers in your code.

CodePudding user response：

Based on your explanation, it looks like result2 is incorrect. It should be -5 because 100% is the second value.

The function assumes that x < y in the array [x, y]

function someMagick(percent, [min, max]) {
  // Range between min and max
  let range = max - min;

  percent /= 100;

  // Finding value between min and max using the percent
  let result = min   (range * percent);

  //Round to hundredths
  return parseFloat(result.toFixed(2));
}

const result1 = someMagick(50, [-26, -5]);
const result2 = someMagick(100, [-26, -5]);

console.log(result1, result2)
// -15.5, -5