So, PHP deals with numbers in a few main ways: integers, floats, and number strings — plus a couple of special types like Infinity and NaN.

If you assign a value like this:

$a = 5;       // integer  
$b = 5.34;    // float  
$c = "25";    // number string  

PHP automatically figures out the type for you. You can double-check it with var_dump(), which tells you both the type and value.

---

Integers

An integer is any whole number — no decimal points. Think of IDs or counters in MemberPress, like $user_count = 5985;.
You can check if something’s an integer using is_int():

var_dump(is_int($user_count));

A few fun facts:

• Integers can be positive or negative.
• PHP can handle huge numbers (up to 9 quintillion on 64-bit systems).
• Once you go past that limit, PHP automatically converts it to a float.
• And, if you do math like 4 * 2.5, the result will be a float because one operand is.

There are also constants like PHP_INT_MAX, PHP_INT_MIN, and PHP_INT_SIZE — great if you’re writing something that relies on system limits.

---

Floats

A float is any number with a decimal or in exponential form, like 10.365 or 7.64E+5.
You can check with is_float():

$x = 10.365;
var_dump(is_float($x));

Floats can get really precise, but only up to about 14 digits before rounding errors sneak in.

PHP also defines constants like PHP_FLOAT_MAX, PHP_FLOAT_MIN, PHP_FLOAT_DIG, and PHP_FLOAT_EPSILON — the last one’s especially nerdy; it’s the tiniest value PHP can distinguish from 1.0.

---

Infinity

If a number goes beyond what PHP can handle — say, dividing something by zero or using 1.9e411 — PHP calls it infinity.
You can check with is_infinite().

$x = 1.9e411;
var_dump(is_infinite($x));

Basically, it’s PHP’s way of saying “this number is too big for me, mate.”

---

NaN (Not a Number)

NaN appears when you try something mathematically impossible, like:

$x = acos(8);
var_dump($x); // NaN

So if you ever see NaN in your debug logs — it’s PHP politely telling you your math makes no sense 😅.

---

Numerical Strings

Sometimes you’ll have a number as a string, like something coming from a form input ("5985").
You can use is_numeric() to check if it’s numeric or not:

$x = "59.85" + 100;
var_dump(is_numeric($x)); // true

But note: since PHP 7, hex strings like "0xf4c3b00c" are not considered numeric anymore.

---

Casting

You can convert numbers between types manually using casting:

$x = 23465.768;
$int_cast = (int)$x;   // becomes 23465

$x = "23465.768";
$int_cast = (int)$x;   // becomes 23465

It’s useful when you want to make sure you’re working with an integer — say, when dealing with IDs, timestamps, or any place where decimals don’t make sense.