chapter12 stringbad

hzchenxiaobin · Apr 26, 2023 · ea3ebbb · ea3ebbb
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diff --git a/chapter12/strngbad/a.out b/chapter12/strngbad/a.out
diff --git a/chapter12/strngbad/strngbad.cpp b/chapter12/strngbad/strngbad.cpp
@@ -0,0 +1,35 @@
+#include "strngbad.h"
+#include <cstring>
+
+int StringBad::num_strings = 0;
+
+StringBad::StringBad(const char *s)
+{
+    len = strlen(s);
+    str = new char[len + 1];
+    std::strcpy(str, s);
+    num_strings++;
+    cout << num_strings << ":\"" << str << "\" object created\n";
+}
+
+StringBad::StringBad()
+{
+    len = 4;
+    str = new char[4];
+    std::strcpy(str, "C++");
+    cout << num_strings << ":\"" << str << "\" default object created\n";
+}
+
+StringBad::~StringBad()
+{
+    cout << "\"" << str << "\" object deleted, ";
+    --num_strings;
+    cout << num_strings << " left\n";
+    delete[] str;
+}
+
+std::ostream &operator<<(std::ostream &os, const StringBad &st)
+{
+    os << st.str;
+    return os;
+}
diff --git a/chapter12/strngbad/strngbad.h b/chapter12/strngbad/strngbad.h
@@ -0,0 +1,22 @@
+#ifndef STRNGBAD_H_
+#define STRNGBAD_H_
+
+#include <iostream>
+
+using namespace std;
+
+class StringBad
+{
+private:
+    char *str;
+    int len;
+    static int num_strings;
+
+public:
+    StringBad(const char *s);
+    StringBad();
+    ~StringBad();
+    friend std::ostream &operator<<(std::ostream &os, const StringBad &st);
+};
+
+#endif
diff --git a/chapter12/strngbad/vegnews.cpp b/chapter12/strngbad/vegnews.cpp
@@ -0,0 +1,40 @@
+#include <iostream>
+#include "strngbad.h"
+
+using std::cout;
+void callme1(StringBad &rsb);
+void callme2(StringBad rsb);
+
+int main()
+{
+    using std::endl;
+    {
+        cout << "Starting an inner block.\n";
+        StringBad headline1("Celery Stalks at Midnight");
+        StringBad headline2("Lettuce Prey");
+        StringBad sports("Spinach Leaves Bowl for Dollars");
+        cout << "headline1: " << headline1 << endl;
+        cout << "headline2: " << headline2 << endl;
+        cout << "sports: " << sports << endl;
+
+        callme1(headline1);
+        cout << "headline1: " << headline1 << endl;
+
+        callme2(headline2);
+        cout << "headline2: " << headline2 << endl;
+    }
+
+    return 0;
+}
+
+void callme1(StringBad &rsb)
+{
+    cout << "String passed by reference:\n";
+    cout << " \"" << rsb << "\"\n";
+}
+
+void callme2(StringBad rsb)
+{
+    cout << "String passed by value:\n";
+    cout << " \"" << rsb << "\"\n";
+}
diff --git a/chapter12/strngbad1/a.out b/chapter12/strngbad1/a.out
diff --git a/chapter12/strngbad1/strngbad.cpp b/chapter12/strngbad1/strngbad.cpp
@@ -0,0 +1,55 @@
+#include "strngbad.h"
+#include <cstring>
+
+int StringBad::num_strings = 0;
+
+StringBad::StringBad(const char *s)
+{
+    len = strlen(s);
+    str = new char[len + 1];
+    std::strcpy(str, s);
+    num_strings++;
+    cout << num_strings << ":\"" << str << "\" object created\n";
+}
+
+StringBad::StringBad()
+{
+    len = 4;
+    str = new char[4];
+    std::strcpy(str, "C++");
+    cout << num_strings << ":\"" << str << "\" default object created\n";
+}
+
+StringBad::StringBad(const StringBad &st)
+{
+    num_strings++;
+    len = st.len;
+    str = new char[len + 1];
+    std::strcpy(str, st.str);
+    cout << num_strings << ": \"" << str << "\" object created\n";
+}
+
+StringBad::~StringBad()
+{
+    cout << "\"" << str << "\" object deleted, ";
+    --num_strings;
+    cout << num_strings << " left\n";
+    delete[] str;
+}
+
+std::ostream &operator<<(std::ostream &os, const StringBad &st)
+{
+    os << st.str;
+    return os;
+}
+
+StringBad &StringBad::operator=(const StringBad &st)
+{
+    if (this == &st)
+        return *this;
+    delete[] str;
+    len = st.len;
+    str = new char[len + 1];
+    std::strcpy(str, st.str);
+    return *this;
+}
diff --git a/chapter12/strngbad1/strngbad.h b/chapter12/strngbad1/strngbad.h
@@ -0,0 +1,25 @@
+#ifndef STRNGBAD_H_
+#define STRNGBAD_H_
+
+#include <iostream>
+
+using namespace std;
+
+class StringBad
+{
+private:
+    char *str;
+    int len;
+    static int num_strings;
+
+public:
+    StringBad(const char *s);
+    StringBad();
+    StringBad(const StringBad & s);
+    ~StringBad();
+
+    StringBad &operator=(const StringBad & st);
+    friend std::ostream &operator<<(std::ostream &os, const StringBad &st);
+};
+
+#endif
diff --git a/chapter12/strngbad1/vegnews.cpp b/chapter12/strngbad1/vegnews.cpp
@@ -0,0 +1,40 @@
+#include <iostream>
+#include "strngbad.h"
+
+using std::cout;
+void callme1(StringBad &rsb);
+void callme2(StringBad rsb);
+
+int main()
+{
+    using std::endl;
+    {
+        cout << "Starting an inner block.\n";
+        StringBad headline1("Celery Stalks at Midnight");
+        StringBad headline2("Lettuce Prey");
+        StringBad sports("Spinach Leaves Bowl for Dollars");
+        cout << "headline1: " << headline1 << endl;
+        cout << "headline2: " << headline2 << endl;
+        cout << "sports: " << sports << endl;
+
+        callme1(headline1);
+        cout << "headline1: " << headline1 << endl;
+
+        callme2(headline2);
+        cout << "headline2: " << headline2 << endl;
+    }
+
+    return 0;
+}
+
+void callme1(StringBad &rsb)
+{
+    cout << "String passed by reference:\n";
+    cout << " \"" << rsb << "\"\n";
+}
+
+void callme2(StringBad rsb)
+{
+    cout << "String passed by value:\n";
+    cout << " \"" << rsb << "\"\n";
+}