javascript数组查询

const arr = [1, 2, 3, 4, 5];
const result = [];
for (let i = 0; i < arr.length; i++) {
  if (arr[i] % 2 === 0) {
    result.push(arr[i]);
  }
}
console.log(result); // [2, 4]

const arr = [1, 2, 3, 4, 5];
const result = arr.filter(item => item % 2 === 0);
console.log(result); // [2, 4]

const arr = [1, 2, 3, 4, 5];
const result = arr.find(item => item % 2 === 0);
console.log(result); // 2

const arr = [1, 2, 3, 4, 5];
const result = arr.reduce((acc, item) => {
  if (item % 2 === 0) {
    acc.push(item);
  }
  return acc;
}, []);
console.log(result); // [2, 4]