使用没有开关的案例 - 这是如何工作的？

Question

I saw this code on codewars - It reminded me of a switch as it has cases yet no switch. How does the cases word work?

function basicOp(operation, value1, value2){
  let cases = {
    '+': value1 + value2,
    '-': value1 - value2,
    '*': value1 * value2,
    '/': value1 / value2
  };
  return cases[operation]
}

Answer 1

 function basicOp(operation, value1, value2){ let cases = { '+': value1 + value2, '-': value1 - value2, '*': value1 * value2, '/': value1 / value2 }; return cases[operation] } console.log(basicOp('+', 2, 3)) console.log(basicOp('-', 3, 1)) console.log(basicOp('*', 2, 6)) console.log(basicOp('/', 4, 2))

This has nothing to do with switch . It's an object with attributes, where the operator is passed as the key in order to get its corresponding value and perform an arithmetic operation.