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C++ Data Types
course content

Conteúdo do Curso

C++ Data Types

C++ Data Types

1. Introduction
OverviewArithmetic OperationsDivision int and doubleStandard MathSpecifying a Type
2. Numerical Data Types
Overview of Integer TypesApplications of Integer TypesType Modifiers for VariablesWorking with Floating-Point NumbersDouble-Precision Numbers
3. Text Data Type
Character Data TypeString Data TypeAccessing and Manipulating String ElementsCommon String MethodsString Manipulation PracticeSearching Within Strings
4. Other Data Types and Concepts
Boolean Data TypeBoolean ExpressionsVoid Data TypeAutomatic Type DeductionUnsigned Data TypesImplicit Type ConversionExplicit Type Conversion

book
Searching Within Strings

Method find()

Sometimes, you may need to search for specific text within a string. This can be done using the .find() or .rfind() methods. Let’s begin with the .find() method.

h

find

copy

              
1

            
str.find("text to find")

It returns the index of the first character of the first match.

cpp

main

copy

              
1234567

            
#include <iostream>

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

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.find("code", 3) << std::endl; // __de(code)finity
}

Method rfind()

You can also locate the last occurrence of some text using the .rfind() method.

h

rfind

copy

              
1

            
str.rfind("text to find")

While .find() retrieves the first occurrence of text, .rfind() finds the last occurrence and stands for reverse find.

cpp

main

copy

              
12345678

            
#include <iostream>

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

Note

If no match is found, both .find() and .rfind() return a special value, string::npos. This value represents no position and indicates that the search was unsuccessful.

cpp

main

copy

              
12345678

            
#include <iostream>

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

Swipe to show code editor

Create a program that prints "Found code" if the string contains "code", and "No code" if it doesn’t.

  1. Write a condition to check for no match using .find() or .rfind(). Refer to the hint if needed.
  2. Replace the "___" placeholders with "Found code" or "No code", based on your if statement.

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Tudo estava claro?

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Seção 3. Capítulo 6
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book
Searching Within Strings

Method find()

Sometimes, you may need to search for specific text within a string. This can be done using the .find() or .rfind() methods. Let’s begin with the .find() method.

h

find

copy

              
1

            
str.find("text to find")

It returns the index of the first character of the first match.

cpp

main

copy

              
1234567

            
#include <iostream>

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

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.find("code", 3) << std::endl; // __de(code)finity
}

Method rfind()

You can also locate the last occurrence of some text using the .rfind() method.

h

rfind

copy

              
1

            
str.rfind("text to find")

While .find() retrieves the first occurrence of text, .rfind() finds the last occurrence and stands for reverse find.

cpp

main

copy

              
12345678

            
#include <iostream>

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

Note

If no match is found, both .find() and .rfind() return a special value, string::npos. This value represents no position and indicates that the search was unsuccessful.

cpp

main

copy

              
12345678

            
#include <iostream>

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

Swipe to show code editor

Create a program that prints "Found code" if the string contains "code", and "No code" if it doesn’t.

  1. Write a condition to check for no match using .find() or .rfind(). Refer to the hint if needed.
  2. Replace the "___" placeholders with "Found code" or "No code", based on your if statement.

Switch to desktopMude para o desktop para praticar no mundo realContinue de onde você está usando uma das opções abaixo
Tudo estava claro?

Como podemos melhorá-lo?

Obrigado pelo seu feedback!

Seção 3. Capítulo 6
Switch to desktopMude para o desktop para praticar no mundo realContinue de onde você está usando uma das opções abaixo
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