int 32 vs. int 64 in C++

Key takeaways:
The int32 can store integer values ranging from -2,147,483,648 to 2,147,483,647. In contrast, int64 can store integer values ranging from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807.
The int32 type uses less memory, suitable for storing smaller integers. On the other hand, int64 requires more memory and is suitable to handle larger values.

int32 and int64 are types of variables used in the C++ programming language to hold whole numbers (integers). int32 holds smaller numbers and int64 holds larger numbers. The 32 or 64 next to int indicates how many bits of information the variable can store, which determines the range of numbers it can hold.

`int32` (`int`)

32-bit integers can store integer values ranging from $-2,147,483,648$ to $2,147,483,647$ . It's used for storing whole numbers that don't require a large range of values.

`int64` (`long long`)

64-bit integer data type can store integer values ranging from $-9,223,372,036,854,775,808$ to $9,223,372,036,854,775,807$ . It can store larger whole numbers compared to int32 and is used when you need to work with very large integers.

Code example

Let's write code to demonstrate the difference between int32 and int64 in C++:

#include <iostream>
int main() {
    // int32 example
    int int32Var = 2147483647;  // Maximum value for int32
    std::cout << "int32Var: " << int32Var << std::endl;
    // Attempt to exceed int32 range
    int32Var = 2147483648;  // One more than the maximum value for int32
    std::cout << "int32Var after exceeding range: " << int32Var << std::endl;  // Output will be unexpected due to overflow
    // int64 example
    long long int int64Var = 9223372036854775807;  // Maximum value for int64
    std::cout << "int64Var: " << int64Var << std::endl;
    // Attempt to exceed int64 range
    int64Var = 9223372036854775808;  // One more than the maximum value for int64
    std::cout << "int64Var after exceeding range: " << int64Var << std::endl;  // Output will be correct
    return 0;
}

Code explanation

Line 5: We declare an int32 variable int32Var and assign it the maximum value for int32 (2147483647).

Line 9: We attempt to assign int32Var a value that is one more than the maximum value for int32 (2147483648). This causes an overflow, and the output will be unexpected.

Line 13: Then, we declare an int64 variable int64Var and assign it the maximum value for int64 (9223372036854775807).

Line 17: Finally, we attempt to assign int64Var a value one more than the maximum value for int64 (9223372036854775808). This causes an overflow, and the output will be unexpected.

Let's summarize the key differences between int32 and int64 in the following table:

Frequently asked questions

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Are int32 and int64 signed or unsigned?

Both are signed by default, allowing for negative and positive values.

What happens if I assign an int64 value to an int32 variable?

It can result in overflow if the int64 value exceeds int32 limits, leading to incorrect results.

How can we store more than 64-bit integers in C++?

In C++, you can store integers larger than 64 bits using the __int128 type (available in GCC and Clang) for 128-bit integers, or by utilizing libraries like GMP (GNU Multiple Precision) for arbitrary-precision arithmetic. Alternatively, you can implement manual storage using std::string or std::vector<int> for custom large number handling.

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Key differences	`int32`	`int64`
Size	32 bits or 4 bytes	64 bits or 8 bytes
Range	-2,147,483,648 to 2,147,483,647	-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
Memory usage	Lower	Higher
Use case	Suitable for smaller integers, like indexes and counts	Ideal for large numbers, financial calculations, and high-precision data

int 32 vs. int 64 in C++

`int32` (`int`)

`int64` (`long long`)

Code example

Code explanation

int32 vs. int64

Conclusion

Frequently asked questions

Are int32 and int64 signed or unsigned?

What happens if I assign an int64 value to an int32 variable?

How can we store more than 64-bit integers in C++?

int 32 vs. int 64 in C++

int32 (int)

int64 (long long)

Code example

Code explanation

int32 vs. int64

Conclusion

Frequently asked questions

Are int32 and int64 signed or unsigned?

What happens if I assign an int64 value to an int32 variable?

How can we store more than 64-bit integers in C++?

`int32` (`int`)

`int64` (`long long`)