test

README.md

@@ -1 +0,0 @@
-#   垃圾分类小程序服务端

test.php

@@ -28,10 +28,24 @@
 //$s2 = "dotcoo";
 //$s3 = "hello dotcoo";
 //var_dump(substr($s1, -strlen($s2)) === $s2);
-function insert($sql, $db_conn = null, $types = null, ...$_)
-{
-    var_dump($types);
+/*
+ * 生成随机字符串
+ * @param int $length 生成随机字符串的长度
+ * @param string $char 组成随机字符串的字符串
+ * @return string $string 生成的随机字符串
+ */
+function str_rand($length = 32, $char = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ') {
+    if(!is_int($length) || $length < 0) {
+        return false;
+    }
+
+    $string = '';
+    for($i = $length; $i > 0; $i--) {
+        $string .= $char[mt_rand(0, strlen($char) - 1)];
+    }
+
+    return $string;
 }
 
-insert("123", $types = "ffff");
+var_dump(str_rand(5));