How Can I Accurately Verify Array Equality in PHP?

Verifying Array Equality in PHP

Determining if two arrays are identical in size, index, and value is a common task in programming. In PHP, there are several ways to approach this.

Comparison Operators

The most straightforward method involves using comparison operators to evaluate equality. However, as you noticed in your code snippet, using the !== operator alone is insufficient. This operator tests for non-identity, not strict equality. To ensure accurate equality checks, consider using the following:

• $arraysAreEqual = ($a == $b): This checks for strict value equality. It returns TRUE if $a and $b have the same key/value pairs.
• $arraysAreEqual = ($a === $b): This is a strict equality check that also considers the type of each element. It returns TRUE if $a and $b have the same key/value pairs in the same order and of the same types.

Array Operators

PHP also provides dedicated array operators for comparison. One important distinction to note is that the inequality operator is !=, while the non-identity operator is !==. This mirrors the distinction between the equality operator == and the identity operator ===.

Therefore, your code snippet can be modified to accurately check for array inequality using the non-identity operator:

if (($_POST['atlOriginal'] !== $oldAtlPosition)
    or ($_POST['atl'] !== $aext)
    or ($_POST['sidesOriginal'] !== $oldSidePosition)
    or ($_POST['sidesOriginal'] !== $sideext)) {

    echo "enter";
}

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