diff --git a/String.cpp b/String.cpp
index c0e3deb..3ec4b01 100644
--- a/String.cpp
+++ b/String.cpp
@@ -5,12 +5,13 @@
 
 
 
-String::String()
+String::String() noexcept
 :_str(nullptr)
 {}
 
 // string must be null-terminated
 String::String(const char* string)
+:String()
 {
     auto size = std::strlen(string) + 1;    // make space for null-terminator
     auto data = new char[size];
@@ -19,7 +20,7 @@ String::String(const char* string)
     _str = new StringValue(data);           // initialize new StringValue with data
 }
 
-String::String(const String& other)
+String::String(const String& other) noexcept
 {
     _str = other._str;
     _str->operator++();
@@ -32,7 +33,7 @@ String& String::operator=(String other)     // take parameter by value: can bind
     return *this;
 }
 
-String::~String()
+String::~String() noexcept
 {
     if (_str)
         _str->operator--(); // the ref-counting is done by StringValue, no need to do that here
@@ -45,7 +46,7 @@ void swap(String& s1, String& s2) noexcept
     swap(s1._str, s2._str);
 }
 
-String::String(String&& other) : String()   // init via default ctor so _str is a nullptr
+String::String(String&& other) noexcept : String()   // init via default ctor so _str is a nullptr
 { swap(*this, other); }
 
 String String::operator+(const String& rhs) const
@@ -120,7 +121,7 @@ Char String::operator[](size_t index)
     return Char(_str->index_of(&const_cast<char&>(const_cast<const String*>(this)->operator[](index))), *this);
 }
 
-size_t String::size() const
+size_t String::size() const noexcept
 {
     if (_str)
         return _str->size();
diff --git a/String.h b/String.h
index 75eab5f..13a9a9f 100644
--- a/String.h
+++ b/String.h
@@ -18,12 +18,12 @@ private:
 
 public:
 
-    String();
+    String() noexcept;
     String(const char*);
-    String(const String&);
+    String(const String&) noexcept;
     String& operator=(String);
-    String(String&&);
-    ~String();
+    String(String&&) noexcept;
+    ~String() noexcept;
 
     friend void swap(String&, String&) noexcept;
     String operator+(const String&) const;
@@ -34,7 +34,7 @@ public:
     const char& operator[](size_t) const;
     Char operator[](size_t);
 
-    size_t size() const;    // does not include null-terminator
+    size_t size() const noexcept;    // does not include null-terminator
     const char* c_str() const;
 
     friend std::istream& operator>>(std::istream&, String&);
diff --git a/StringValue.cpp b/StringValue.cpp
index cee8e78..f322f61 100644
--- a/StringValue.cpp
+++ b/StringValue.cpp
@@ -4,14 +4,14 @@
 
 
 
-StringValue::StringValue(char* data)
+StringValue::StringValue(char* data) noexcept
 :_data(data), _size(std::strlen(data) + 1), _refs(1)
 {}
 
-void StringValue::operator++()
+void StringValue::operator++() noexcept
 { _refs++; }
 
-void StringValue::operator--()
+void StringValue::operator--() noexcept
 {
     _refs--;
     if (_refs == 0)
@@ -33,10 +33,10 @@ const char& StringValue::operator[](size_t index) const
 char& StringValue::operator[](size_t index)
 { return const_cast<char&>(const_cast<const StringValue*>(this)->operator[](index)); }
 
-StringValue::operator const char*() const
+StringValue::operator const char*() const noexcept
 { return _data; }
 
-size_t StringValue::size() const
+size_t StringValue::size() const noexcept
 { return _size - 1; }
 
 size_t StringValue::index_of(char* c) const
diff --git a/StringValue.h b/StringValue.h
index 5cebb8a..cc8205b 100644
--- a/StringValue.h
+++ b/StringValue.h
@@ -21,12 +21,12 @@ private:
 
 public:
 
-    StringValue(char* data);
-    void operator++();
-    void operator--();
+    StringValue(char* data) noexcept;
+    void operator++() noexcept;
+    void operator--() noexcept;
     const char& operator[](size_t index) const;
     char& operator[](size_t index);
-    operator const char*() const;
-    size_t size() const;
+    operator const char*() const noexcept;
+    size_t size() const noexcept;
     size_t index_of(char* c) const;
 };
\ No newline at end of file