How to Check if a String contains given Substring in C++ - Step by Step Examples

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How to Check if a String contains given Substring in C++ ?

Answer

To check if a string contains a given substring in C++, you can use the 'find' method of the std::string class.

✐ Examples

1 Check if a String contains given Substring using 'find' method

In this example,

We create a function 'containsSubstring' that takes a string and a substring as input.
We use the 'find' method of the string object to check if the substring is present in the string.
If the substring is found, the index of the first occurrence is returned; otherwise, 'std::string::npos'.
Finally, we print the result.

C++ Program

#include <iostream>
#include <string>

bool containsSubstring(const std::string& str, const std::string& substr) {
    return str.find(substr) != std::string::npos;
}

int main() {
    std::string str = "Hello World";
    std::string substr = "World";
    bool contains = containsSubstring(str, substr);
    std::cout << "String contains substring '" << substr << "': " << std::boolalpha << contains << std::endl;
    return 0;
}

Output

String contains substring 'World': true

Summary

In this tutorial, we learned How to Check if a String contains given Substring in C++ language with well detailed examples.