Javascript array.includes()用法及代碼示例

array.includes()是JavaScript中的內置函數，用於了解數組中是否存在特定元素，因此返回true或false，即如果存在該元素，則返回true或false
用法:

array.includes(searchElement)

參數：
searchElement：是要搜索的元素。
返回值：
它返回一個布爾值，即True或False。

例子：

Input:
[1, 2, 3, 4, 5].includes(2);
Output:
true
Input:
[1, 2, 3, 4, 5].includes(9);
Output:
false

JavaScript代碼顯示array.includes()函數的工作方式：
代碼1：

<script> 
  
    // Taking input as an array A 
    // having some elements. 
    var A = [ 1, 2, 3, 4, 5 ]; 
  
    // include() function is called to 
    // test whether the searching element 
    // is present in given array or not. 
     a = A.includes(2) 
  
    // Printing result of function. 
    document.write(a); 
</script>

輸出：

 true

代碼2：

<script> 
   // Taking input as an array A 
   // having some elements. 
    var name = [ 'gfg', 'cse', 'geeks', 'portal' ]; 
  
   // include() function is called to 
   // test whether the searching element 
   // is present in given array or not. 
    a = name.includes('cat') 
  
    // Printing result of function 
    document.write(a); 
</script>

輸出：

 false

相關用法

注：本文由純淨天空篩選整理自Kanchan_Ray大神的英文原創作品 JavaScript | array.includes() function。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。