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Javascript typedArray.copyWithin()用法及代码示例


typedArray.copyWithin()是JavaScript中的内置函数,用于在同一typedArray中的指定位置复制typedArray的某些元素。

用法:

typedArray.copyWithin(target, start, end)

参数:它接受下面指定的三个参数-


  • target:它是从中复制元素的起始索引位置。
  • start:它是从其开始复制元素的起始索引位置,其默认值为typedArray的起始索引。
  • end:它是可选的,它是要复制的元素之前的结束位置索引,并且其默认值是typedArray的结束。

返回值:复制过程完成后,它将返回修改后的数组。

JavaScript代码显示此函数的工作方式:

代码1:
<script> 
  
   // Constructing a new typedArray "A" 
   // with some elements 
   const A = new Uint8Array([ 5, 10, 15, 20, 25, 30, 35, 40 ]); 
  
   // Calling copyWithin function to copy  
   // element from index position 0 and 
   // element from index 4 to 5 
   A.copyWithin(0, 4, 5); 
  
   // Printing a new modified array 
   document.write(A); 
     
</script>

输出:

25,10,15,20,25,30,35,40

代码2:

<script> 
  
   // Constructing some new typedArrays 
   // with some elements 
   const A = new Uint8Array([ 5, 10, 15, 20, 25, 30, 35, 40 ]); 
   const B = new Uint8Array([ 5, 10, 15, 20, 25, 30, 35, 40 ]); 
   const C = new Uint8Array([ 5, 10, 15, 20, 25, 30, 35, 40 ]); 
   const D = new Uint8Array([ 5, 10, 15, 20, 25, 30, 35, 40 ]); 
   const E = new Uint8Array([ 5, 10, 15, 20, 25, 30, 35, 40 ]); 
  
   // Calling copyWithin function with different 
   // parameters 
   a = A.copyWithin(0, 5); 
   b = B.copyWithin(1, 4); 
   c = C.copyWithin(0, 4, 5); 
   d = D.copyWithin(2, 3, 5); 
   e = E.copyWithin(0, 1, 4); 
  
   // Printing new modified arrays 
   document.write(a +"<br>"); 
   document.write(b +"<br>"); 
   document.write(c +"<br>"); 
   document.write(d +"<br>"); 
   document.write(e); 
     
</script>

输出:

30,35,40,20,25,30,35,40
5,25,30,35,40,30,35,40
25,10,15,20,25,30,35,40
5,10,20,25,25,30,35,40
10,15,20,20,25,30,35,40


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注:本文由纯净天空筛选整理自ShivamKD大神的英文原创作品 JavaScript | typedArray.copyWithin() with Examples。非经特殊声明,原始代码版权归原作者所有,本译文未经允许或授权,请勿转载或复制。