1 files changed, 40 insertions, 0 deletions
diff --git a/sort_recursively.php b/sort_recursively.php
new file mode 100644
index 0000000..4d089e1
--- /dev/null
+++ b/sort_recursively.php
@@ -0,0 +1,40 @@
+<?php
+
+/**
+ * Comparison function for custom sort. Tries to achieve a canonical sort order across PHP versions
+ * by sorting primarily by type, secondarily by value.
+ * @param mixed $a
+ * @param mixed $b
+ *
+ * @return int
+ */
+function byTypeAndValue($a, $b): int
+{
+    if (gettype($a) !== gettype($b)) {
+        return gettype($a) <=> gettype($b);
+    } else {
+        return $a <=> $b;
+    }
+}
+
+/**
+ * Sort an array by its values, recursively
+ * @param array &$array
+ */
+function sortRecursively(array &$array): void
+{
+    // Sequential array, re-index after sorting
+    if (array_keys($array) === range(0, count($array) - 1)) {
+        usort($array, 'byTypeAndValue');
+    }
+    // Associative array, maintain keys
+    else {
+        uasort($array, 'byTypeAndValue');
+    }
+    
+    foreach ($array as &$value) {
+        if (is_array($value)) {
+            sortRecursively($value);
+        }
+    }
+}