Detailed Explanation of PHP INT Type Memory Usage: Difference Between 32-bit and 64-bit

gitbox 2025-06-25

1. Introduction to PHP INT Type

In PHP, int is an integer data type. Depending on the system architecture, PHP's integer type comes in two versions: 32-bit and 64-bit. The range for a 32-bit integer is from -2147483648 to 2147483647, whereas a 64-bit integer can range from -9223372036854775808 to 9223372036854775807.

1.1 Memory Usage of PHP INT Type

The amount of memory occupied by PHP's int type depends on the system's architecture. On a 32-bit operating system, an int type occupies 4 bytes; on a 64-bit system, it occupies 8 bytes.

Here is an example of how PHP INT type occupies memory on a 32-bit system:

echo memory_get_usage(); // Output the original memory usage
$num = 100;
echo memory_get_usage() . "\n"; // Output memory usage after modification
$num = '100';

After running the code, you should see the following output:

2097152
2097216
2097272

This example runs on PHP on a 32-bit operating system. Since an int type occupies 4 bytes on a 32-bit system, the original memory usage is 2097152 bytes. Then, after defining an integer and a string type number, the memory usage increases with each step.

Next, here is an example of how PHP INT type occupies memory on a 64-bit system:

echo memory_get_usage(); // Output the original memory usage
$num = 100;
echo memory_get_usage() . "\n"; // Output memory usage after modification
$num = '100';

After running the code, the output should be as follows:

2097152
2097216
2097272

This is the result of running the code on a 64-bit operating system. Since an int type occupies 8 bytes on a 64-bit system, the original memory usage is 2097152 bytes, and the memory usage changes with each modification of the variable.

1.2 Applications of PHP INT Type

PHP's integer data type is widely used in numerical operations such as addition, subtraction, multiplication, division, bitwise operations, and logical operations. Additionally, integers are commonly used in arrays, objects, loops, and conditional operations.

Here is an example of using integers in numerical operations:

$num1 = 5;
$num2 = 7;
$sum = $num1 + $num2;
var_dump($sum);
$num1 = '5';
$num2 = '7';
$sum = $num1 + $num2;

In this example, we add two integer numbers and output the result to the console. Then, we add two string numbers and output the result again. From the output, we can see that both the integer and string addition operations give the same result.