diff --git a/practical_exercises/key_exercises/中括号重载.cpp b/practical_exercises/key_exercises/中括号重载.cpp
index f89aaec..a9a2137 100644
--- a/practical_exercises/key_exercises/中括号重载.cpp
+++ b/practical_exercises/key_exercises/中括号重载.cpp
@@ -1,51 +1,58 @@
-//Eg8-9.cpp
 #include <iostream>
 #include <cstring>
 using namespace std;
-struct Person{                		//ְ��������Ϣ�Ľṹ
-		double salary;
-		char *name;
+struct Person
+{ //职工基本信息的结构
+    double salary;
+    char *name;
 };
-class SalaryManaege{
-		Person *employ;          	 //���ְ����Ϣ������
-		int max;                  		//�����±��Ͻ�
-		int n;                    		//�����е�ʵ��ְ������
+class SalaryManaege
+{
+    Person *employ; //存放职工信息的数组
+    int max;        //数组下标上界
+    int n;          //数组中的实际职工人数
 public:
-	SalaryManaege(int Max=0){
-		max=Max;
-		n=0;
-		employ=new Person[max];
-	}
-	//�������������ǿ���ֱ���ڷ�����ֵ��ֱ��ʹ��
-    double &operator[](char *Name) {       	//����[]����������
-		Person *p;
-		for(p=employ;p<employ+n;p++)   
-			//������ڴ���   	
-			if(strcmp(p->name,Name)==0) 
-				return p->salary;
-		//�������������
-		p=employ + n++; 
-		p->name=new char[strlen(Name)+1];
-		strcpy(p->name,Name);
-		p->salary=0;
-		return p->salary;
-	}
+    SalaryManaege(int Max = 0)
+    {
+        max = Max;
+        n = 0;
+        employ = new Person[max];
+    }
+    //返回引用特性是可以直接在放在左值，直接使用
+    double &operator[](char *Name)
+    { //重载[]，返回引用
+        Person *p;
+        for (p = employ; p < employ + n; p++)
+            //如果存在处理
+            if (strcmp(p->name, Name) == 0)
+                return p->salary;
+        //不存在情况处理
+        p = employ + n++;
+        p->name = new char[strlen(Name) + 1];
+        strcpy(p->name, Name);
+        p->salary = 0;
+        return p->salary;
+    }
 
-	void display(){      								
-		for(int i=0;i<n;i++)
-			cout<<employ[i].name<<"   "<<employ[i].salary<<endl;
-		}
+    void display()
+    {
+        for (int i = 0; i < n; i++)
+            cout << employ[i].name << "   " << employ[i].salary << endl;
+    }
+    ~SalaryManaege() {
+        delete employ;
+    }
 };
-int main(){
+int main()
+{
     SalaryManaege s(3);
-    s["����"]=2188.88;
-    s["��˹"]=1230.07;
-    s["����"]=3200.97;
-    cout<<"����\t"<<s["����"]<<endl;          cout<<"��˹\t"<<s["��˹"]<<endl;
-    cout<<"����\t"<<s["����"]<<endl;
-  
-    cout<<"-------��Ϊdisplay�����--------\n\n";
-    s.display();
-    system("pause");
-}
+    s["张三"] = 2188.88;
+    s["里斯"] = 1230.07;
+    s["王无"] = 3200.97;
+    cout << "张三\t" << s["张三"] << endl;
+    cout << "里斯\t" << s["里斯"] << endl;
+    cout << "王无\t" << s["王无"] << endl;
 
+    cout << "-------下为display的输出--------\n\n";
+    s.display();
+}