How to Java String substring in C++

The Java String substring function is used to extract a portion of a string. It takes two parameters: the starting index and the ending index of the substring. The starting index is inclusive, meaning the character at that index is included in the substring, while the ending index is exclusive, meaning the character at that index is not included in the substring. If only the starting index is provided, the substring will include all characters from that index to the end of the string. The substring function returns a new string that contains the extracted portion of the original string. Keep reading below to learn how to Java String substring in C++.

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Java String substring in C++ With Example Code

Java’s String class has a method called substring() that allows you to extract a portion of a string. This can be useful for a variety of tasks, such as parsing data or manipulating text. If you’re working in C++, you might be wondering how to achieve the same functionality. Fortunately, there are several ways to Java String substring in C++.

One approach is to use the substr() method of the std::string class. This method takes two arguments: the starting index of the substring and the length of the substring. Here’s an example:

std::string str = "Hello, world!"; std::string substr = str.substr(7, 5); std::cout << substr << std::endl; // Output: world

In this example, we create a string called str and assign it the value "Hello, world!". We then call the substr() method on str, passing in the starting index of 7 (which corresponds to the "w" in "world") and a length of 5. This creates a new string called substr that contains the substring "world". We then print out the value of substr using std::cout.

Another approach is to use the string_view class, which was introduced in C++17. This class provides a lightweight, non-owning view of a string. Here's an example:

#include #include

int main() { std::string_view str = "Hello, world!"; std::string_view substr = str.substr(7, 5); std::cout << substr << std::endl; // Output: world return 0; }

In this example, we include the header and create a string_view called str that points to the string "Hello, world!". We then call the substr() method on str, passing in the starting index of 7 and a length of 5. This creates a new string_view called substr that points to the substring "world". We then print out the value of substr using std::cout.

Both of these approaches allow you to achieve the same functionality as Java's String substring() method in C++. Choose the approach that works best for your particular use case.

Equivalent of Java String substring in C++

In conclusion, the equivalent function to Java's String substring() in C++ is the substr() function. This function allows you to extract a portion of a string by specifying the starting index and the length of the substring. It is a powerful tool that can be used in a variety of applications, from data processing to text manipulation. By understanding the similarities and differences between these two functions, you can easily transition between Java and C++ programming languages and take advantage of the unique features of each. Whether you are a beginner or an experienced programmer, the substr() function is an essential tool to have in your programming arsenal.