用于验证元素是否存在于数组中的函数

function linearSearch(arr, target) {
  for (let i = 0; i < arr.length; i++) {
    if (arr[i] === target) {
      return true;
    }
  }
  return false;
}

const array = [1, 2, 3, 4, 5];
console.log(linearSearch(array, 3)); // 输出: true
console.log(linearSearch(array, 6)); // 输出: false

const array = [1, 2, 3, 4, 5];
console.log(array.includes(3)); // 输出: true
console.log(array.includes(6)); // 输出: false

const array = [1, 2, 3, 4, 5];
console.log(array.indexOf(3) !== -1); // 输出: true
console.log(array.indexOf(6) !== -1); // 输出: false

const array = [1, 2, NaN];
console.log(array.some(x => Number.isNaN(x))); // 输出: true

const array = [{ id: 1 }, { id: 2 }];
const target = { id: 1 };
console.log(array.some(item => item.id === target.id)); // 输出: true