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C++ Data Types
course content

Зміст курсу

C++ Data Types

C++ Data Types

1. Introduction
OverviewArithmetic OperationsDivision int and doubleMath in C++Specifying a Type
2. Numerical Data Types
IntegersUsing IntegersType modifierFloatDoubleNumerical Data Types Summary
3. Text Data Type
CharStringIndexing a StringWorking With StringChanging The String PracticeFinding Text in a StringStrings in Memory
4. Other Data Types and Concepts
BooleanBoolean ExpressionsVoidAuto UnsignedImplicit Type ConversionExplicit Type Conversion

bookFinding Text in a String

In some cases, you may want to look for specific text in your string. It can be done using .find() or.rfind() method. Let's start with the .find() method. Here is the syntax:

It returns the index of the first character of the first match. Let's look at the example:

cpp

main

copy

              
1234567

            
#include <iostream>

int main()
{
    std::string str = "codecodefinity";
    std::cout << str.find("code", 3) << std::endl; // __de(code)finity
}

You can also specify the position of the first character in the string to be considered in the search.
It can be done using the pos argument. Any characters before the pos index are ignored in a search.

Here is an example of finding the first "code" starting from a 3-rd character.

cpp

main

copy

              
1234567

            
#include <iostream>

int main()
{
    std::string str = "codecodefinity";
    std::cout << str.rfind("code") << std::endl; // code(code)finity
}

The .find(str2) method finds the first occurrence of str2.
Alternatively you can find the last character of the last occurrence of str2 using the .rfind(str2) method. Here is the syntax of .rfind():

Here is an example:

cpp

main

copy

              
12345678

            
#include <iostream>

int main()
{
    std::string str = "codecodefinity";
    std::cout << str.rfind("abc") << std::endl;
    std::cout << std::string::npos << std::endl;
}

So .rfind() is a reversed find.
Instead of finding the first occurrence, it finds the last one.
And instead of returning the first character of occurrence, it returns the last.

Note

If there is no match, both .find() and .rfind() return some weird number, npos of string.
This number can be accessed with string::npos.

cpp

main

copy

              
12345678910

            
#include <iostream>
using namespace std;

int main()
{
  string str = "codecodefinity";
  cout << str.rfind("abc") << endl;
  cout << string::npos << endl;
  return 0;
}

Завдання

Build a program that outputs "Found code" if "code" is in a string, and "No code" if "code" is not in a string.

  • Write a statement to check if there is no match using .find() or .rfind(). If you have problems with this step, check out the hint.
  • Fill the "___" gaps with "Found code" or "No code", depending on how you wrote the if statement.

Switch to desktopПерейдіть на комп'ютер для реальної практикиПродовжуйте з того місця, де ви зупинились, використовуючи один з наведених нижче варіантів
Все було зрозуміло?

Як ми можемо покращити це?

Дякуємо за ваш відгук!

Секція 3. Розділ 6
toggle bottom row

bookFinding Text in a String

In some cases, you may want to look for specific text in your string. It can be done using .find() or.rfind() method. Let's start with the .find() method. Here is the syntax:

It returns the index of the first character of the first match. Let's look at the example:

cpp

main

copy

              
1234567

            
#include <iostream>

int main()
{
    std::string str = "codecodefinity";
    std::cout << str.find("code", 3) << std::endl; // __de(code)finity
}

You can also specify the position of the first character in the string to be considered in the search.
It can be done using the pos argument. Any characters before the pos index are ignored in a search.

Here is an example of finding the first "code" starting from a 3-rd character.

cpp

main

copy

              
1234567

            
#include <iostream>

int main()
{
    std::string str = "codecodefinity";
    std::cout << str.rfind("code") << std::endl; // code(code)finity
}

The .find(str2) method finds the first occurrence of str2.
Alternatively you can find the last character of the last occurrence of str2 using the .rfind(str2) method. Here is the syntax of .rfind():

Here is an example:

cpp

main

copy

              
12345678

            
#include <iostream>

int main()
{
    std::string str = "codecodefinity";
    std::cout << str.rfind("abc") << std::endl;
    std::cout << std::string::npos << std::endl;
}

So .rfind() is a reversed find.
Instead of finding the first occurrence, it finds the last one.
And instead of returning the first character of occurrence, it returns the last.

Note

If there is no match, both .find() and .rfind() return some weird number, npos of string.
This number can be accessed with string::npos.

cpp

main

copy

              
12345678910

            
#include <iostream>
using namespace std;

int main()
{
  string str = "codecodefinity";
  cout << str.rfind("abc") << endl;
  cout << string::npos << endl;
  return 0;
}

Завдання

Build a program that outputs "Found code" if "code" is in a string, and "No code" if "code" is not in a string.

  • Write a statement to check if there is no match using .find() or .rfind(). If you have problems with this step, check out the hint.
  • Fill the "___" gaps with "Found code" or "No code", depending on how you wrote the if statement.

Switch to desktopПерейдіть на комп'ютер для реальної практикиПродовжуйте з того місця, де ви зупинились, використовуючи один з наведених нижче варіантів
Все було зрозуміло?

Як ми можемо покращити це?

Дякуємо за ваш відгук!

Секція 3. Розділ 6
toggle bottom row

bookFinding Text in a String

In some cases, you may want to look for specific text in your string. It can be done using .find() or.rfind() method. Let's start with the .find() method. Here is the syntax:

It returns the index of the first character of the first match. Let's look at the example:

cpp

main

copy

              
1234567

            
#include <iostream>

int main()
{
    std::string str = "codecodefinity";
    std::cout << str.find("code", 3) << std::endl; // __de(code)finity
}

You can also specify the position of the first character in the string to be considered in the search.
It can be done using the pos argument. Any characters before the pos index are ignored in a search.

Here is an example of finding the first "code" starting from a 3-rd character.

cpp

main

copy

              
1234567

            
#include <iostream>

int main()
{
    std::string str = "codecodefinity";
    std::cout << str.rfind("code") << std::endl; // code(code)finity
}

The .find(str2) method finds the first occurrence of str2.
Alternatively you can find the last character of the last occurrence of str2 using the .rfind(str2) method. Here is the syntax of .rfind():

Here is an example:

cpp

main

copy

              
12345678

            
#include <iostream>

int main()
{
    std::string str = "codecodefinity";
    std::cout << str.rfind("abc") << std::endl;
    std::cout << std::string::npos << std::endl;
}

So .rfind() is a reversed find.
Instead of finding the first occurrence, it finds the last one.
And instead of returning the first character of occurrence, it returns the last.

Note

If there is no match, both .find() and .rfind() return some weird number, npos of string.
This number can be accessed with string::npos.

cpp

main

copy

              
12345678910

            
#include <iostream>
using namespace std;

int main()
{
  string str = "codecodefinity";
  cout << str.rfind("abc") << endl;
  cout << string::npos << endl;
  return 0;
}

Завдання

Build a program that outputs "Found code" if "code" is in a string, and "No code" if "code" is not in a string.

  • Write a statement to check if there is no match using .find() or .rfind(). If you have problems with this step, check out the hint.
  • Fill the "___" gaps with "Found code" or "No code", depending on how you wrote the if statement.

Switch to desktopПерейдіть на комп'ютер для реальної практикиПродовжуйте з того місця, де ви зупинились, використовуючи один з наведених нижче варіантів
Все було зрозуміло?

Як ми можемо покращити це?

Дякуємо за ваш відгук!

In some cases, you may want to look for specific text in your string. It can be done using .find() or.rfind() method. Let's start with the .find() method. Here is the syntax:

It returns the index of the first character of the first match. Let's look at the example:

cpp

main

copy

              
1234567

            
#include <iostream>

int main()
{
    std::string str = "codecodefinity";
    std::cout << str.find("code", 3) << std::endl; // __de(code)finity
}

You can also specify the position of the first character in the string to be considered in the search.
It can be done using the pos argument. Any characters before the pos index are ignored in a search.

Here is an example of finding the first "code" starting from a 3-rd character.

cpp

main

copy

              
1234567

            
#include <iostream>

int main()
{
    std::string str = "codecodefinity";
    std::cout << str.rfind("code") << std::endl; // code(code)finity
}

The .find(str2) method finds the first occurrence of str2.
Alternatively you can find the last character of the last occurrence of str2 using the .rfind(str2) method. Here is the syntax of .rfind():

Here is an example:

cpp

main

copy

              
12345678

            
#include <iostream>

int main()
{
    std::string str = "codecodefinity";
    std::cout << str.rfind("abc") << std::endl;
    std::cout << std::string::npos << std::endl;
}

So .rfind() is a reversed find.
Instead of finding the first occurrence, it finds the last one.
And instead of returning the first character of occurrence, it returns the last.

Note

If there is no match, both .find() and .rfind() return some weird number, npos of string.
This number can be accessed with string::npos.

cpp

main

copy

              
12345678910

            
#include <iostream>
using namespace std;

int main()
{
  string str = "codecodefinity";
  cout << str.rfind("abc") << endl;
  cout << string::npos << endl;
  return 0;
}

Завдання

Build a program that outputs "Found code" if "code" is in a string, and "No code" if "code" is not in a string.

  • Write a statement to check if there is no match using .find() or .rfind(). If you have problems with this step, check out the hint.
  • Fill the "___" gaps with "Found code" or "No code", depending on how you wrote the if statement.

Switch to desktopПерейдіть на комп'ютер для реальної практикиПродовжуйте з того місця, де ви зупинились, використовуючи один з наведених нижче варіантів
Секція 3. Розділ 6
Switch to desktopПерейдіть на комп'ютер для реальної практикиПродовжуйте з того місця, де ви зупинились, використовуючи один з наведених нижче варіантів
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