Otherwise, static_cast the return value of std::string::length() to an int. If you’re C++20 capable, use std::ssize() to get the length as a signed value. It parses str interpreting its content as an integral number of the specified base, which is returned as a value of type long int. std::string::length() returns an unsigned value. std::stol(): This function converts the string, provided as an argument in the function call, to long int. Reminder: We need to be careful not to mix signed and unsigned values. Sample output: Enter your full name: John Doe For simplicity, count any spaces in the name as a letter. As output, tell the user the sum of their age and the number of letters in their name (use the std::string::length() member function to get the length of the string). Write a program that asks the user to enter their full name and their age. We encourage you to start experimenting with strings now, and we’ll cover additional string capabilities later. It is a function of the C standard library and can be implemented in C++. Fortunately, you don’t need to understand these complexities to use std::string for simple tasks, like basic string input and output. The strtol() method is used to convert strings to long integers. Std::string is complex, leveraging many language features that we haven’t covered yet. If you need constexpr strings, use std::string_view instead (discussed in lesson 4.18 - Introduction to std::string_view). Thats undefined the pointer is uninitialised. This happens because constexpr std::string isn’t supported at all in C++17 or earlier, and only works in very limited cases in C++20/23. Simply remove the excess declaration: // convert str to long long int called user3 char endptr NULL user3 strtoll (str.cstr (), &endptr, 10) You have a similar issue with your const char line3, which you declare inside the function, never assign anything to, then construct a string out of. Just like normal variables, you can initialize or assign values to std::string objects as you would expect: #include D also provides the special type string to represent ASCII strings. We can create objects of type std::string just like other objects: In lesson 4.15 - Literals, we introduced C-style string literals: #include
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