2.js 499 B

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  1. //! 数组的includes方法
  2. // includes() 方法用来判断一个数组是否包含一个指定的值,根据情况,如果包含则返回 true,否则返回 false。
  3. const array1 = [1, 2, 3];
  4. console.log(array1.includes(2));
  5. console.log(array1.includes(2, -2));
  6. // expected output: true
  7. const pets = ['cat', 'dog', 'bat'];
  8. console.log(pets.includes('cat')); // expected output: true
  9. console.log(pets.includes('cat', 1)); // false
  10. console.log(pets.includes('at'));
  11. // expected output: false