重构嵌套的 If-Else 语句

Question

could you help me give me some ideas how to refactor the following nested if-statement?

function priceCalculator(age, height) {

  if (age == "under 18") {
      if (height <= 1.5) {
          price = 6.18;
      } else if (height > 1.5 && height <= 1.8) {
          price = 5.59;
      } else if (height > 1.8) {
          price = 5.37;
      }
  } else if (age == "18-50") {
      if (height <= 1.5) {
          price = 7.38;
      } else if (height > 1.5 && height <= 1.8) {
          price = 6.19;
      } else if (height > 1.8) {
          price = 7.22;
      }
  } else if (age == "over 50") {
      if (height <= 1.5) {
          price = 8.48;
      } else if (height > 1.5 && height <= 1.8) {
          price = 8.53;
      } else if (height > 1.8) {
          price = 8.17;
      }
  }

  console.log(price);
}

It gets pretty ugly, once I introduce even more age and height categories. Is there a possibility to kind of shorten the code and make it prettier? Switch statements are problematic, because the second variable is an integer.

Answer 1

For the general case when the prices change for each age and height, start with an object indexed by age. Inside, for each age, you could have an array of height thresholds and their associated price. .find in the array the first matching threshold given the height, and return the associated price.

const config = {
    'under 18': [
        // [Height must be <= this, to get this price]
        [1.5, 6.18],
        [1.8, 5.59],
        [Infinity, 5.37]
    ],
    '18-50': [ // change as needed
        [1.5, 6.18],
        [1.8, 5.59],
        [Infinity, 5.37]
    ],
    // ...
}
function priceCalculator(age, height) {
    return config[age]
        .find(([threshold]) => height <= threshold)
        [1];
}