first commit

code/SmallCart/SmallCartMain/data/js/utils.js

@@ -0,0 +1,20 @@
+class Utils {
+    $(className) {
+        return document.querySelector(className);
+    }
+
+
+    debounce(fn, delay = 1000) {
+        let timer = null //借助闭包
+        return function () {
+            if (timer) {
+                clearTimeout(timer)
+            }
+            timer = setTimeout(fn, delay) // 简化写法
+        }
+    }
+
+    
+}
+
+var { $, debounce } = new Utils();