diff --git a/tests/std/core/007_array_search.phpt b/tests/std/core/007_array_search.phpt
new file mode 100644
index 00000000..818143aa
--- /dev/null
+++ b/tests/std/core/007_array_search.phpt
@@ -0,0 +1,89 @@
+--TEST--
+Array functions - in_array, array_search, array_key_exists, array_keys, array_values
+--FILE--
+<?php
+
+echo "== in_array ==\n";
+var_dump(in_array(2, [1, 2, 3]));
+var_dump(in_array('2', [1, 2, 3], true));
+var_dump(in_array(4, [1, 2, 3]));
+
+echo "== array_search ==\n";
+var_dump(array_search(2, [1, 2, 3]));
+var_dump(array_search('2', [1, 2, 3], true));
+var_dump(array_search(4, [1, 2, 3]));
+
+echo "== array_key_exists ==\n";
+$arr = ['a' => 1, 'b' => 2, 'c' => null];
+var_dump(array_key_exists('a', $arr));
+var_dump(array_key_exists('c', $arr));
+var_dump(array_key_exists('d', $arr));
+var_dump(array_key_exists(0, [10, 20, 30]));
+
+echo "== array_keys ==\n";
+print_r(array_keys(['a' => 1, 'b' => 2, 'c' => 3]));
+print_r(array_keys([10, 20, 30]));
+print_r(array_keys(['a' => 1, 'b' => 2, 'c' => 2], 2));
+print_r(array_keys(['a' => 2, 'b' => '2', 'c' => 2], '2', true));
+
+echo "== array_values ==\n";
+print_r(array_values(['a' => 1, 'b' => 2, 'c' => 3]));
+print_r(array_values([10, 20, 30]));
+print_r(array_values(['x' => 1, 'y' => 2, 'z' => 3]));
+
+?>
+--EXPECT--
+== in_array ==
+bool(true)
+bool(false)
+bool(false)
+== array_search ==
+int(1)
+bool(false)
+bool(false)
+== array_key_exists ==
+bool(true)
+bool(true)
+bool(false)
+bool(true)
+== array_keys ==
+Array
+(
+    [0] => a
+    [1] => b
+    [2] => c
+)
+Array
+(
+    [0] => 0
+    [1] => 1
+    [2] => 2
+)
+Array
+(
+    [0] => b
+    [1] => c
+)
+Array
+(
+    [0] => b
+)
+== array_values ==
+Array
+(
+    [0] => 1
+    [1] => 2
+    [2] => 3
+)
+Array
+(
+    [0] => 10
+    [1] => 20
+    [2] => 30
+)
+Array
+(
+    [0] => 1
+    [1] => 2
+    [2] => 3
+)
diff --git a/tests/std/core/008_datetime.phpt b/tests/std/core/008_datetime.phpt
new file mode 100644
index 00000000..45b5835a
--- /dev/null
+++ b/tests/std/core/008_datetime.phpt
@@ -0,0 +1,31 @@
+--TEST--
+Date/time functions - time, date, strtotime
+--FILE--
+<?php
+
+echo "== time() ==\n";
+$t = time();
+var_dump($t > 1000000000);
+
+echo "== date() ==\n";
+$d = date("Y");  // current year, always works
+echo "year: $d\n";
+var_dump(strlen(date("Y-m-d")) === 10);
+
+echo "== strtotime() ==\n";
+$ts = strtotime("2021-01-01 00:00:00 UTC");
+var_dump($ts > 0);
+var_dump(strtotime("not a valid date"));
+var_dump(is_int(strtotime("+1 day", 1609459200)));
+
+?>
+--EXPECT--
+== time() ==
+bool(true)
+== date() ==
+year: 2026
+bool(true)
+== strtotime() ==
+bool(true)
+bool(false)
+bool(true)
diff --git a/tests/std/core/009_string_extra.phpt b/tests/std/core/009_string_extra.phpt
new file mode 100644
index 00000000..e293dfc1
--- /dev/null
+++ b/tests/std/core/009_string_extra.phpt
@@ -0,0 +1,36 @@
+--TEST--
+String functions - dirname, basename, strtr
+--FILE--
+<?php
+
+echo "== dirname() ==\n";
+echo dirname("/etc/passwd") . "\n";
+echo dirname("/etc/") . "\n";
+echo dirname("/") . "\n";
+echo dirname("relative/path/file.txt") . "\n";
+
+echo "== basename() ==\n";
+echo basename("/etc/passwd") . "\n";
+echo basename("/etc/passwd", ".passwd") . "\n";
+echo basename("relative/path/file.php", ".php") . "\n";
+echo "[" . basename("/") . "]\n";
+
+echo "== strtr() ==\n";
+echo strtr("hello world", "wo", "WO") . "\n";
+echo strtr("abcdef", "abc", "123") . "\n";
+
+?>
+--EXPECT--
+== dirname() ==
+/etc
+/
+/
+relative/path
+== basename() ==
+passwd
+passwd
+file
+[]
+== strtr() ==
+hellO WOrld
+123def
diff --git a/tests/std/core/010_fs_math.phpt b/tests/std/core/010_fs_math.phpt
new file mode 100644
index 00000000..c9e9ee30
--- /dev/null
+++ b/tests/std/core/010_fs_math.phpt
@@ -0,0 +1,42 @@
+--TEST--
+Filesystem and math functions - is_dir, is_file, round
+--FILE--
+<?php
+
+echo "== is_dir() ==\n";
+var_dump(is_dir("/"));
+var_dump(is_dir("/nonexistent_path_xyz123"));
+var_dump(is_dir("/etc"));
+
+echo "== is_file() ==\n";
+var_dump(is_file("/nonexistent_file_xyz123"));
+var_dump(is_file(__FILE__));
+
+echo "== round() ==\n";
+var_dump(round(3.4));
+var_dump(round(3.6));
+var_dump(round(3.14159, 2));
+var_dump(round(3.5));
+var_dump(round(4.5));
+var_dump(round(-1.5));
+var_dump(round(1234.5678, 2));
+var_dump(round(1234.5678, -2));
+
+?>
+--EXPECT--
+== is_dir() ==
+bool(true)
+bool(false)
+bool(true)
+== is_file() ==
+bool(false)
+bool(true)
+== round() ==
+float(3)
+float(4)
+float(3.14)
+float(4)
+float(5)
+float(-2)
+float(1234.57)
+float(1200)
diff --git a/tests/std/core/011_misc.phpt b/tests/std/core/011_misc.phpt
new file mode 100644
index 00000000..6e0cadc9
--- /dev/null
+++ b/tests/std/core/011_misc.phpt
@@ -0,0 +1,41 @@
+--TEST--
+Misc functions - md5, version_compare, print_r
+--FILE--
+<?php
+
+echo "== md5() ==\n";
+echo md5("hello") . "\n";
+echo md5("") . "\n";
+var_dump(strlen(md5("test", true)) === 16);
+
+echo "== version_compare() ==\n";
+var_dump(version_compare("1.2.3", "1.2.3"));
+var_dump(version_compare("1.2.3", "1.2.4"));
+var_dump(version_compare("2.0.0", "1.9.9"));
+var_dump(version_compare("1.0", "1.0.0"));
+
+echo "== print_r() ==\n";
+$s = print_r([1, 2, 3], true);
+echo $s;
+$s2 = print_r("hello", true);
+echo $s2;
+
+?>
+--EXPECT--
+== md5() ==
+5d41402abc4b2a76b9719d911017c592
+d41d8cd98f00b204e9800998ecf8427e
+bool(true)
+== version_compare() ==
+int(0)
+int(-1)
+int(1)
+int(-1)
+== print_r() ==
+Array
+(
+    [0] => 1
+    [1] => 2
+    [2] => 3
+)
+hello