YouTipPhp Is_Float Function
## PHP is_float() Function
The `is_float()` function in PHP is a built-in variable handling function used to determine whether a given variable is of the float (floating-point) data type.
In PHP, a float (also known as a "double" or "real number") is a number with a decimal point or a number in exponential form.
---
### Syntax
```php
bool is_float ( mixed $var )
```
#### Parameters
* **`$var`**: The variable you want to evaluate. This can be of any data type (`mixed`).
#### Return Value
* Returns `true` if `$var` is a float, otherwise returns `false`.
---
### Aliases
PHP provides two alias functions that behave identically to `is_float()`:
* **`is_double()`**
* **`is_real()`** *(Note: `is_real()` has been **deprecated** as of PHP 7.4.0 and **removed** in PHP 8.0.0. It is highly recommended to use `is_float()` instead).*
---
### Code Examples
#### Basic Usage
The following example demonstrates how `is_float()` evaluates different types of values:
```php
```
#### Output:
```text
This is a float value.
bool(false)
bool(false)
bool(false)
bool(false)
bool(true)
```
---
### Key Considerations
#### 1. Numeric Strings vs. Floats
`is_float()` strictly checks the **data type** of the variable, not its content. If a variable contains a numeric string (such as `"12.5"`), `is_float()` will return `false` because the type is `string`, not `float`.
If you need to check whether a variable is a number or a numeric string (commonly found in HTML form inputs or API payloads), you should use **`is_numeric()`** instead.
```php
$numeric_string = "12.5";
var_dump(is_float($numeric_string)); // Returns bool(false)
var_dump(is_numeric($numeric_string)); // Returns bool(true)
```
#### 2. NaN and Infinity
Special floating-point values like `NAN` (Not a Number) and `INF` (Infinity) are technically of the `float` type. Therefore, `is_float()` will return `true` for them.
```php
var_dump(is_float(NAN)); // Returns bool(true)
var_dump(is_float(INF)); // Returns bool(true)
```