空指针异常

CodeCoderCoding · CodeCoderCoding · commit 1b71ae09dcd9 · 2022-04-27T21:23:43.000+08:00
diff --git a/src/CException/NullException.java b/src/CException/NullException.java
@@ -0,0 +1,21 @@
+package CException;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * @ClassName NullException
+ * @Description
+ * @Author yuzhihua
+ * @Date 2022/4/20 9:17
+ * @Version 1.0.0
+ **/
+public class NullException {
+    public static void main(String[] args) {
+        List<Long> idList=new ArrayList<>();
+        idList=null;
+        for(Long id:idList){
+            System.out.println(id);
+        }
+    }
+}
