Numerical Data Types
Whole numbers
Integer data types are the most commonly used for whole numbers. The int data type can hold values within the range of -2,147,483,648 to 2,147,483,647.
main.cpp
That happens because when you declare an int variable, it allocates precisely 4 bytes of your PC's memory. And numbers above 2147483647 (or below -2147483648) do not fit inside those 4 bytes. Luckily, other data types available can allocate you more(or less) space for your needs. Here is the table:
| Data Type | ||
short | 2 bytes | |
int | 4 bytes | |
long | 8 bytes |
So you can use long to store large numbers (e.g., World's population). You can also use short if you are sure your number will not exceed the -32,768 to 32,767 range (e.g., storing a user's age). Using short will take up less space.
main.cpp
Note
Be careful with the data type you choose. If the range of a type is exceeded, the C++ compiler will not tell you this, and you will get an unexpected value without knowing something is wrong.
Floating point numbers
The data types above are designed to store whole numbers. If we tried to assign 1.6 to one of those, here is what we would get:
main.cpp
The int type ignores the decimal part of a number. The same story with short or long. To store the floating point(decimal) numbers, we should use either float or double data type.
| Data Type | ||
float | ||
double |
Here is an example of using double to store 1.6.
main.cpp
Note
Since the
floattype only has a precision of seven digits, the number123.456789is already out of its range. It can lead to inaccurate results(as shown in the example below). So it is better to usedoubleby default unless you are surefloat's precision is enough.
main.cpp
Obviously, you can use float or double to store whole numbers since those are decimal numbers with a decimal part equal to 0. However, as a good practice, if a variable stores values that can only be whole numbers (e.g., population or likes), short/int/long should be used.
main.cpp
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Conteúdo do Curso
C++ Introduction
4. Introduction to Program Flow
5. Introduction to Functions
C++ Introduction
Numerical Data Types
Whole numbers
Integer data types are the most commonly used for whole numbers. The int data type can hold values within the range of -2,147,483,648 to 2,147,483,647.
main.cpp
That happens because when you declare an int variable, it allocates precisely 4 bytes of your PC's memory. And numbers above 2147483647 (or below -2147483648) do not fit inside those 4 bytes. Luckily, other data types available can allocate you more(or less) space for your needs. Here is the table:
| Data Type | ||
short | 2 bytes | |
int | 4 bytes | |
long | 8 bytes |
So you can use long to store large numbers (e.g., World's population). You can also use short if you are sure your number will not exceed the -32,768 to 32,767 range (e.g., storing a user's age). Using short will take up less space.
main.cpp
Note
Be careful with the data type you choose. If the range of a type is exceeded, the C++ compiler will not tell you this, and you will get an unexpected value without knowing something is wrong.
Floating point numbers
The data types above are designed to store whole numbers. If we tried to assign 1.6 to one of those, here is what we would get:
main.cpp
The int type ignores the decimal part of a number. The same story with short or long. To store the floating point(decimal) numbers, we should use either float or double data type.
| Data Type | ||
float | ||
double |
Here is an example of using double to store 1.6.
main.cpp
Note
Since the
floattype only has a precision of seven digits, the number123.456789is already out of its range. It can lead to inaccurate results(as shown in the example below). So it is better to usedoubleby default unless you are surefloat's precision is enough.
main.cpp
Obviously, you can use float or double to store whole numbers since those are decimal numbers with a decimal part equal to 0. However, as a good practice, if a variable stores values that can only be whole numbers (e.g., population or likes), short/int/long should be used.
main.cpp
Tudo estava claro?
