Notice: This page requires JavaScript to function properly.
Please enable JavaScript in your browser settings or update your browser.Auto | Other Data Types and Concepts
C++ Data Types
course content

Contenido del Curso

C++ Data Types

C++ Data Types

1. Introduction
OverviewArithmetic OperationsDivision int and doubleMath in C++Specifying a Type
2. Numerical Data Types
IntegersUsing IntegersType modifierFloatDoubleNumerical Data Types Summary
3. Text Data Type
CharStringIndexing a StringWorking With StringChanging The String PracticeFinding Text in a StringStrings in Memory
4. Other Data Types and Concepts
BooleanBoolean ExpressionsVoidAuto UnsignedImplicit Type ConversionExplicit Type Conversion

bookAuto

Although C++ is a typed language, you can use auto when initializing a variable to determine the type automatically. This feature was introduced in C++14 and does not work with older versions.
Here is an example:

cpp

main

copy

              
12345678910

            
#include <iostream>

int main()
{
    auto num = 9;
    auto str = "I am string";
    
    std::cout << num << std::endl;
    std::cout << str << std::endl;
}

Note that it is harder to catch errors when using auto. Consider the example:

cpp

main

copy

              
1234567891011

            
#include <iostream>

int main()
{
    auto num1 = 9;
    auto num2 = 12;
    auto num3 = 15000;
    auto calculations = num1 / num2 * num3;
    
    std::cout << calculations;
}

Specifying types would help us understand code better and find what's wrong:

cpp

main

copy

              
1234567891011

            
#include <iostream>

int main()
{
    float num1 = 9;
    float num2 = 12;
    float num3 = 15000;
    float calculations = num1 / num2 * num3;
    
    std::cout << calculations;
}

Note

Any of num1, num2 or num3 should be float to output the correct result.

Nevertheless, auto is widely used in range-based for loops since it is a versatile method of iterating over arrays and other containers. Just use the following syntax for iterating over arr:

cpp

main

copy

              
123456789

            
#include <iostream>

int main()
{
    int num_arr[5] = {1, 5, 10, 15, 20};
    
    for (auto num : num_arr)
        std::cout << num << " ";
}

It also can be used when the type is long to type but is clear from the context and can't lead to incorrect results.

¿Todo estuvo claro?

¿Cómo podemos mejorarlo?

¡Gracias por tus comentarios!

Sección 4. Capítulo 4
some-alt