添加base62进制转换

src/Library/Base62.php

@@ -0,0 +1,46 @@
+<?php
+/**
+ * 62进制数据转换
+ *
+ * @
+ */
+class Base62
+{
+    /**
+     * @var string $chars 62进制对应的数据
+     */
+    public static $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+
+    /**
+     * base 62 转 10 进制
+     * @param string $str 62 进制
+     * @return bool|string
+     */
+    public function to10($str)
+    {
+        $out = 0;
+        $len = strlen($str) - 1;
+        for ($t = 0; $t <= $len; $t++) {
+            $out = $out + strpos(self::$chars, substr($str, $t, 1)) * pow(62, $len - $t);
+        }
+        return substr(sprintf("%f", $out), 0, -7);
+    }
+
+    /**
+     * 10进制转62进制
+     *
+     * @param int $i 10 进制数据
+     * @return string
+     */
+    public function to62($i)
+    {
+        if ($i == 0) return 'a';
+        $out = '';
+        for ($t = floor(log10($i) / log10(62)); $t >= 0; $t--) {
+            $a = floor($i / pow(62, $t));
+            $out = $out . substr(self::$chars, $a, 1);
+            $i = $i - ($a * pow(62, $t));
+        }
+        return $out;
+    }
+}