### Why is this statement true in PHP?

The result of this script:

``var_dump((0x0FFFFFFF)); var_dump((0xF0FFFFFF)); var_dump((0x0FFFFFFF | 0xF0FFFFFF)); var_dump((0xFFFFFFFF)); var_dump(((0x0FFFFFFF | 0xF0FFFFFF)) != (0xFFFFFFFF));``

is

``int(268435455)float(4043309055)int(-1)float(4294967295)bool(true)``

PHP converts hexadecimal numbers larger than 31 bits into floats, as an integer is signed, and can therefore only hold 31 positive bits.

Hexadecimal numbers are unsigned, so the conversion makes sense.

The first "or" operation converts the float into an integer, as it doesn't make sense to perform an "or" on a float. So PHP converts the float to an int for the or, the result is an int, but the next hexadecimal conversion is a float, and the values are not the same.

To convert the float to a integer in a bitwise fashion, OR it with 0x0:

``var_dump((0xFFFFFFFF | 0x0)); var_dump(((0x0FFFFFFF | 0xF0FFFFFF)) != (0xFFFFFFFF | 0x0));``

results in

``int(-1)bool(false)``

Source: stackoverflow.com

Method #2

The result of the script you provided is:

```scss```int(268435455)
float(4043309055)
int(-1)
float(4294967295)
bool(true)
``````

The `var_dump()` function is used to output the values of the expressions to the console.

1. `var_dump((0x0FFFFFFF));` - The value `0x0FFFFFFF` represents the maximum value of a 32-bit unsigned integer in hexadecimal format. The `var_dump()` function outputs an integer value of `268435455` to the console.

2. `var_dump((0xF0FFFFFF));` - The value `0xF0FFFFFF` represents a 32-bit integer with the most significant byte set to `0xF0`. Since the value is greater than the maximum integer value in PHP, it is represented as a float. The `var_dump()` function outputs a float value of `4043309055` to the console.

3. `var_dump((0x0FFFFFFF | 0xF0FFFFFF));` - The bitwise OR operation between `0x0FFFFFFF` and `0xF0FFFFFF` results in `0xFFFFFFFF`, which represents the maximum value of a 32-bit unsigned integer. The `var_dump()` function outputs an integer value of `-1` to the console.

4. `var_dump((0xFFFFFFFF));` - The value `0xFFFFFFFF` represents the maximum value of a 32-bit unsigned integer in hexadecimal format. The `var_dump()` function outputs a float value of `4294967295` to the console.

5. `var_dump(((0x0FFFFFFF | 0xF0FFFFFF)) != (0xFFFFFFFF));` - The expression evaluates to `true` because the bitwise OR operation between `0x0FFFFFFF` and `0xF0FFFFFF` results in `0xFFFFFFFF`, which is not equal to the maximum value of a 32-bit unsigned integer. The `var_dump()` function outputs a boolean value of `true` to the console.