From 6ccfa49cadd48b550c4a58932532ea96ebff6e50 Mon Sep 17 00:00:00 2001
From: jmz <1125378902@qq.com>
Date: Fri, 2 Jun 2023 18:13:29 +0800
Subject: [PATCH] optimize 5

---
 docs/source/05.operator.md | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/docs/source/05.operator.md b/docs/source/05.operator.md
index a9000e4..7d195de 100644
--- a/docs/source/05.operator.md
+++ b/docs/source/05.operator.md
@@ -130,6 +130,10 @@ function f(uint a, uint b) pure public returns (uint) {
 
 #### for 循环中，++i 更省钱
 
+通过汇编执行流程比较发现, i++比++i 多做了一次 `DUP(3 gas)`和`POP(2 gas)`操作, 10次循环正好是50gas, 
+多出来的 22 gas是 因为 test2 会比 test1 优先命中的原因.
+
+
 ```
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.17;
@@ -151,6 +155,25 @@ contract Test {
 }
 ```
 
+更省gas 的操作
+```
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.17;
+
+contract Test {
+    // 25153 gas
+    function test1() public pure returns (uint256 temp) {
+        for (uint256 index = 0; index < 10; ) {
+            temp += index;
+            unchecked{
+                // index++ 与++index 不会出现gas上的差异
+                index++;
+            }
+        }
+    }
+}
+```
+
 ### 赋值运算符
 
 - `= `(简单赋值)