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Square brackets are used for arrays in JavaScript. An array is an ordered data structure used to store a sequence of values. Square brackets have two main uses: one is to access array elements by element index, and the other is to modify array elements.
The meaning of square brackets in JavaScript
square brackets, that is, [
and ]
, is mainly used to represent arrays in JavaScript. An array is an ordered data structure used to store a sequence of values.
The syntax of square brackets
<code class="javascript">const array = [element1, element2, ..., elementN];</code>
Where:
array
is the name of the array. element1
, element2
, ..., elementN
are the values stored in the array. Use of square brackets
Square brackets have two main uses:
1. Access array elements
We can access specific elements in an array using square brackets and element index. Indexing starts at 0, which represents the first element in the array. For example:
<code class="javascript">const array = [1, 2, 3, 4, 5]; console.log(array[2]); // 输出:3</code>
2. Modify array elements
You can also use square brackets and element indexes to modify elements in the array. For example:
<code class="javascript">const array = [1, 2, 3, 4, 5]; array[2] = 10; console.log(array); // 输出:[1, 2, 10, 4, 5]</code>
Note:
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