Why Does 5,6,8,7 = 8 in JavaScript?

JavaScript Quirk: Understanding 5,6,8,7 = 8

In JavaScript, the peculiar behavior of 5,6,8,7 resulting in the value 8 may seem enigmatic. Let's delve into the intricacies of this expression.

The initial brackets [5,6,8,7] represent an array of numbers. However, the second set of brackets [1,2] cannot be an array because arrays must be enclosed in square brackets. Therefore, we interpret [1,2] as an array subscript operation.

In JavaScript, array subscript operations access a specific element of an array based on an index. In this case, the index is [1,2], which is an expression that evaluates to the number 3. Thus, the expression 5,6,8,7 is equivalent to 5,6,8,7.

The result of this subscript operation is the element at index 3 of the array [5,6,8,7]. Since arrays in JavaScript are zero-indexed, index 3 corresponds to the fourth element in the array, which is the value 8.

To summarize, 5,6,8,7 evaluates to 8 because:

• The second set of brackets [1,2] represents an array subscript operation.
• The index [1,2] evaluates to 3.
• The subscript operation accesses the element at index 3 in the array [5,6,8,7], which is the value 8.

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