From b9894472c5627c9f88d0ff2b388664ee12259f94 Mon Sep 17 00:00:00 2001
From: zhumingming <zhumingming1314@gmail.com>
Date: Mon, 8 Sep 2025 06:17:53 +0800
Subject: [PATCH] =?UTF-8?q?=E8=AE=BE=E7=BD=AE=E4=B8=80=E4=BA=9B=E6=B5=8B?=
 =?UTF-8?q?=E8=AF=95?=
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---
 .vscode/launch.json                           | 43 +++++++++++++++++++
 .../chapter2/item6/RomanNumerals.java         |  2 +-
 src/effectivejava/chapter2/item6/Sum.java     |  2 +-
 3 files changed, 45 insertions(+), 2 deletions(-)
 create mode 100644 .vscode/launch.json

diff --git a/.vscode/launch.json b/.vscode/launch.json
new file mode 100644
index 00000000..c43b3684
--- /dev/null
+++ b/.vscode/launch.json
@@ -0,0 +1,43 @@
+{
+  "version": "0.2.0",
+  "configurations": [
+    {
+        "type": "java",
+        "name": "Adult",
+        "request": "launch",
+        "mainClass": "effectivejava.chapter2.item8.Adult",
+        "projectName": "effective-java-3e-source-code_616714c9"
+    },
+    {
+        "type": "java",
+        "name": "Run RomanNumerals with args",
+        "request": "launch",
+        "mainClass": "effectivejava.chapter2.item6.RomanNumerals",
+        "args": [
+            "5",
+            "1000"
+        ]
+    },
+    {
+        "type": "java",
+        "name": "Run Sum with args",
+        "request": "launch",
+        "mainClass": "effectivejava.chapter2.item6.Sum",
+        "args": [
+            "1"
+        ]
+    },
+    {
+        "type": "java",
+        "name": "Run Operation with args",
+        "request": "launch",
+        "mainClass": "effectivejava.chapter7.item42.Operation",
+        "args": [
+            "2",
+            "3"
+        ]
+    }
+]
+}
+
+
diff --git a/src/effectivejava/chapter2/item6/RomanNumerals.java b/src/effectivejava/chapter2/item6/RomanNumerals.java
index bf451409..8e0ad65c 100644
--- a/src/effectivejava/chapter2/item6/RomanNumerals.java
+++ b/src/effectivejava/chapter2/item6/RomanNumerals.java
@@ -26,7 +26,7 @@ public static void main(String[] args) {
         for (int i = 0; i < numSets; i++) {
             long start = System.nanoTime();
             for (int j = 0; j < numReps; j++) {
-                b ^= isRomanNumeralSlow("MCMLXXVI");  // Change Slow to Fast to see performance difference
+                b ^= isRomanNumeralFast("MCMLXXVI");  // Change Slow to Fast to see performance difference
             }
             long end = System.nanoTime();
             System.out.println(((end - start) / (1_000. * numReps)) + " μs.");
diff --git a/src/effectivejava/chapter2/item6/Sum.java b/src/effectivejava/chapter2/item6/Sum.java
index 2a7a7ebd..9fd501be 100644
--- a/src/effectivejava/chapter2/item6/Sum.java
+++ b/src/effectivejava/chapter2/item6/Sum.java
@@ -5,7 +5,7 @@
 // Hideously slow program! Can you spot the object creation? (Page 24)
 public class Sum {
     private static long sum() {
-        Long sum = 0L;
+        long sum = 0L;
         for (long i = 0; i <= Integer.MAX_VALUE; i++)
             sum += i;
         return sum;