What is the output of the function var_dump(array(1, 2, 3));?

The output of the function var_dump(array(1, 2, 3)); is indeed array(3) { [0]=> int(1) [1]=> int(2) [2]=> int(3) }. This result comes from the way var_dump() provides a detailed representation of the variable passed to it.

When var_dump() is called with an array, it outputs the type of the variable, the number of elements in the array, and a detailed breakdown of each key-value pair within the array. In this case, it specifies that the variable is an array containing three elements. Each indexed element is then listed along with its index and type. Here, [0]=> int(1) shows that at index 0, there is an integer with the value of 1, and this continues for the other elements.

This differing output structure is particularly useful for debugging because it gives you all necessary information about the array, unlike simpler outputs which may not convey the same level of detail regarding data types and structures. The other choices do not accurately capture this detailed representation that var_dump() provides.