string to int c++

Converting a string to an integer in C++ involves several steps. Here is an explanation for each step:

1. Include the necessary header file: In order to use the string and conversion functions, you need to include the <string> and <cstdlib> header files in your C++ program.

2. Declare a string variable: Begin by declaring a string variable that holds the string value you want to convert to an integer. For example, string str = "123";.

3. Use the stoi() function: The stoi() function is used to convert a string to an integer. It takes the string as input and returns the corresponding integer value. For example, int num = stoi(str); will convert the string "123" to the integer 123.

4. Handle exceptions: It's important to handle exceptions that may occur during the conversion process. If the string cannot be converted to an integer (e.g., if it contains non-numeric characters), an exception of type invalid_argument or out_of_range may be thrown. You can use a try-catch block to handle these exceptions.

That's it! Following these steps will allow you to convert a string to an integer in C++. Remember to include the necessary header files, declare a string variable, use the stoi() function, and handle any exceptions that may arise.