ext/standard: Add is_assoc_array() to detect associative arrays

Author: arshidkv12

ext/standard/array.c

@@ -4385,6 +4385,39 @@ PHP_FUNCTION(array_keys)
 }
 /* }}} */
 
+/* {{{  */
+PHP_FUNCTION(is_assoc_array)
+{
+    zval *arr;
+    zend_array *ht;
+	zend_ulong idx, expected = 0;
+    zend_string *key;
+
+    ZEND_PARSE_PARAMETERS_START(1,1)
+        Z_PARAM_ARRAY(arr)
+    ZEND_PARSE_PARAMETERS_END();
+	
+	ht = Z_ARRVAL_P(arr);
+
+	if (zend_hash_num_elements(ht) == 0) {
+        RETURN_FALSE;
+    }
+
+	if(!HT_IS_PACKED(ht)){
+		RETURN_TRUE;
+	}
+
+    ZEND_HASH_FOREACH_KEY(ht, idx, key) {
+        if (key != NULL || idx != expected++) {
+            RETURN_TRUE; /* associative */
+        }
+    } ZEND_HASH_FOREACH_END();
+
+    RETURN_FALSE;
+
+}
+/* }}} */
+
 /* {{{ Get the key of the first element of the array */
 PHP_FUNCTION(array_key_first)
 {

ext/standard/basic_functions.stub.php

@@ -1696,6 +1696,11 @@ function array_replace_recursive(array $array, array ...$replacements): array {}
  */
 function array_keys(array $array, mixed $filter_value = UNKNOWN, bool $strict = false): array {}
 
+/**
+ * @compile-time-eval
+ */
+function is_assoc_array(array $array): bool {}
+
 /**
  * @compile-time-eval
  */

ext/standard/basic_functions_arginfo.h

@@ -0,0 +1,36 @@
+--TEST--
+Test is_assoc_array() behavior
+--FILE--
+<?php
+
+echo "1. "; var_dump(is_assoc_array(['a' => 'a', 0 => 'b']));
+echo "2. "; var_dump(is_assoc_array([1 => 'a', 0 => 'b']));
+echo "3. "; var_dump(is_assoc_array([1 => 'a', 2 => 'b']));
+echo "4. "; var_dump(is_assoc_array([0 => 'a', 1 => 'b']));
+echo "5. "; var_dump(is_assoc_array(['a', 'b']));
+
+echo "6. "; var_dump(is_assoc_array([]));
+echo "7. "; var_dump(is_assoc_array([1, 2, 3]));
+echo "8. "; var_dump(is_assoc_array(['foo', 2, 3]));
+echo "9. "; var_dump(is_assoc_array([0 => 'foo', 'bar']));
+
+echo "10. "; var_dump(is_assoc_array([1 => 'foo', 'bar']));
+echo "11. "; var_dump(is_assoc_array([0 => 'foo', 'bar' => 'baz']));
+echo "12. "; var_dump(is_assoc_array([0 => 'foo', 2 => 'bar']));
+echo "13. "; var_dump(is_assoc_array(['foo' => 'bar', 'baz' => 'qux']));
+
+?>
+--EXPECT--
+1. bool(true)
+2. bool(true)
+3. bool(true)
+4. bool(false)
+5. bool(false)
+6. bool(false)
+7. bool(false)
+8. bool(false)
+9. bool(false)
+10. bool(true)
+11. bool(true)
+12. bool(true)
+13. bool(true)