在map函数闭包内使用问号运算符的替代方法

condition ? exprIfTrue : exprIfFalse

const numbers = [1, 2, 3, 4, 5];
const doubledOrQuadrupled = numbers.map(num => {
  if (num % 2 === 0) {
    return num * 2;
  } else {
    return num * 4;
  }
});
console.log(doubledOrQuadrupled); // 输出: [4, 4, 12, 8, 20]

const numbers = [1, 2, 3, 4, 5];

function transformNumber(num) {
  return num % 2 === 0 ? num * 2 : num * 4;
}

const doubledOrQuadrupled = numbers.map(transformNumber);
console.log(doubledOrQuadrupled); // 输出: [4, 4, 12, 8, 20]

const numbers = [1, 2, 3, 4, 5];
const multiplierMap = {
  true: 4,
  false: 2
};

const doubledOrQuadrupled = numbers.map(num => num * multiplierMap[num % 2 === 0]);
console.log(doubledOrQuadrupled); // 输出: [4, 4, 12, 8, 20]