To cut it short, here is the question. What will be logged in the console when we run this code snippet? The subsequent element [1,2] cannot function as an array; hence, it operates as an array…

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Learn why [9,8,7,6][1,2] evaluates to 7 and explore similar array operations in JavaScript.

Javascript Interview Question: Why does [9,8,7,6][1,2] = 7 ?

The first brackets create an inline array, the second pair of brackets call the array lookup function based on index. The expression between the second brackets has the comma operator, which evaluates the first part (the 1) and then the second one (the 2) and then returns whatever the last item was. So 2 in this case. Which makes that the argument for the array lookup is 2, so the overall expression evaluates as 7, since that is the 2nd element of the inline array.

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That’s a really good info. Thank you for sharing.

In JavaScript, when you use square brackets directly after an array, it’s interpreted as accessing the element at the index specified within those brackets. Let’s break down the expression <code>[9, 8, 7, 6][1, 2]</code>:
<ol>
<li><code>[9, 8, 7, 6]</code>: This is an array with elements 9, 8, 7, and 6.</li>
<li><code>[1, 2]</code>: This is also an array with elements 1 and 2.</li>
</ol>
When you use <code>[1, 2]</code> immediately after <code>[9, 8, 7, 6]</code>, JavaScript evaluates it as an array expression. However, the comma operator in JavaScript evaluates each expression and returns the last one. In this case, it evaluates <code>1</code> and <code>2</code>, but only returns <code>2</code>. So effectively, <code>[1, 2]</code> is interpreted as just <code>2</code>.
Now, the expression becomes <code>[9, 8, 7, 6][2]</code>, which means you’re accessing the element at index <code>2</code> in the array <code>[9, 8, 7, 6]</code>. Since arrays in JavaScript are zero-indexed, the element at index <code>2</code> is <code>7</code>. Hence, <code>[9, 8, 7, 6][1, 2]</code> evaluates to <code>7</code>.
To clarify, if you intended to access multiple elements from the array <code>[9, 8, 7, 6]</code>, you would need to use another approach, such as using nested arrays or iterating over the indices.

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