Course Content

C++ Data Types

1. Introduction

Overview Arithmetic Operations Division int and double Math in C++Specifying a Type

2. Numerical Data Types

Integers Using Integers Type modifier Float Double Numerical Data Types Summary

3. Text Data Type

Char String Indexing a String Working With String Changing The String Practice Finding Text in a String Strings in Memory

4. Other Data Types and Concepts

Boolean Boolean Expressions Void Auto Unsigned Implicit Type Conversion Explicit Type Conversion

Finding 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:

main


              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.

main


              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:

main


              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.

main


              12345678910
            
#include <iostream>
using namespace std;

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

Task

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 desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Thanks for your feedback!

Section 3. Chapter 6

Finding 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:

main


              1234567
            
#include <iostream>

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

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

main


              1234567
            
#include <iostream>

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

Here is an example:

main


              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.

main


              12345678910
            
#include <iostream>
using namespace std;

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

Task

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 desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Thanks for your feedback!

Section 3. Chapter 6

Finding 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:

main


              1234567
            
#include <iostream>

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

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

main


              1234567
            
#include <iostream>

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

Here is an example:

main


              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.

main


              12345678910
            
#include <iostream>
using namespace std;

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

Task

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 desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Thanks for your feedback!

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:

main


              1234567
            
#include <iostream>

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

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

main


              1234567
            
#include <iostream>

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

Here is an example:

main


              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.

main


              12345678910
            
#include <iostream>
using namespace std;

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

Task

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 desktop for real-world practiceContinue from where you are using one of the options below

Section 3. Chapter 6

Switch to desktop for real-world practiceContinue from where you are using one of the options below