js map 跳过

let newArray = array.map(function(currentValue, index, array) {
  // 返回新数组的元素
});

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

let newNumbers = numbers.map(function(number) {
  if (number % 2 === 0) { // 只处理偶数
    return number * 2;
  }
  // 如果是奇数，不返回任何值，相当于跳过
});

console.log(newNumbers); // 输出: [undefined, 4, undefined, 8, undefined]

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

let newNumbers = numbers
  .filter(function(number) {
    return number % 2 === 0; // 只保留偶数
  })
  .map(function(number) {
    return number * 2; // 对偶数进行处理
  });

console.log(newNumbers); // 输出: [4, 8]

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

let newNumbers = numbers.reduce(function(acc, number) {
  if (number % 2 === 0) {
    acc.push(number * 2); // 只处理偶数并添加到累加器数组中
  }
  return acc;
}, []);

console.log(newNumbers); // 输出: [4, 8]