diff --git a/.gitattributes b/.gitattributes
index db4fefa..8a47153 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1 +1 @@
-*.php linguist-language=JavaScript
\ No newline at end of file
+*.md linguist-language=JavaScript
\ No newline at end of file
diff --git a/05-JavaScript进阶/JavaScript开发积累.md b/05-JavaScript进阶/JavaScript开发积累.md
index 8794758..0b0f26d 100644
--- a/05-JavaScript进阶/JavaScript开发积累.md
+++ b/05-JavaScript进阶/JavaScript开发积累.md
@@ -109,3 +109,17 @@ if (result?.user?.name?.length) {
 
 
 
+### 2020-04-28-字符串添加白名单
+
+```js
+if ('str1' == ('str1' || 'str2')){
+    console.log('smyhvae);
+}
+```
+
+注意，上面的代码，根本就不会走 console.log语句，因为if里面的内容是false。
+
+
+
+
+