How to Check if String starts with Specific Prefix in C++ - Step by Step Examples

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How to Check if String starts with Specific Prefix in C++ ?

Answer

To check if a string starts with a specific prefix in C++, you can use the compare() function or substr() function.

✐ Examples

1 Check if "Hello World" starts with prefix "Hello"

In this example,

We create a string named str1 with a value of "Hello World".
We use the compare() function or substr() function to check if str1 starts with the prefix "Hello".
The compare() function returns 0 if the string starts with the specified prefix; otherwise, it returns a value greater or less than 0.
Finally, we print the result to standard output.

C++ Program

#include <iostream>
#include <string>

int main() {
    std::string str1 = "Hello World";
    bool startsWithHello = str1.compare(0, 5, "Hello") == 0;
    std::cout << "String starts with prefix 'Hello': " << std::boolalpha << startsWithHello << std::endl;
    // or using substr()
    bool startsWithHelloSubstr = str1.substr(0, 5) == "Hello";
    std::cout << "String starts with prefix 'Hello' (using substr()): " << startsWithHelloSubstr << std::endl;
    return 0;
}

Output

String starts with prefix 'Hello': true
String starts with prefix 'Hello' (using substr()): true

2 Check if "apple" starts with prefix "banana"

In this example,

We create a string named str2 with a value of "apple".
We use the compare() function or substr() function to check if str2 starts with the prefix "banana".
The compare() function returns 0 if the string starts with the specified prefix; otherwise, it returns a value greater or less than 0.
Finally, we print the result to standard output.

C++ Program

#include <iostream>
#include <string>

int main() {
    std::string str2 = "apple";
    bool startsWithBanana = str2.compare(0, 6, "banana") == 0;
    std::cout << "String starts with prefix 'banana': " << std::boolalpha << startsWithBanana << std::endl;
    // or using substr()
    bool startsWithBananaSubstr = str2.substr(0, 6) == "banana";
    std::cout << "String starts with prefix 'banana' (using substr()): " << startsWithBananaSubstr << std::endl;
    return 0;
}

Output

String starts with prefix 'banana': false
String starts with prefix 'banana' (using substr()): false

Summary

In this tutorial, we learned How to Check if String starts with Specific Prefix in C++ language with well detailed examples.

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How to Check if String starts with Specific Prefix in C++ - Step by Step Examples

How to Check if String starts with Specific Prefix in C++ ?

Answer

✐ Examples

1 Check if "Hello World" starts with prefix "Hello"

C++ Program

Output

2 Check if "apple" starts with prefix "banana"

C++ Program

Output

Summary

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