Understanding PHP Data Types and the Use of Decimal

In programming, data types are an important concept. PHP, as a loosely typed language, supports a number of data types. However, "Decimal" is not a valid PHP data type.

PHP supports eight primary data types, divided into three categories:

• Scalars: Includes integer, float (or double), boolean, and string data types
• Compounds: Contains array and object data types
• Special: Includes resource and NULL data types

The DECIMAL Misconception

Although the term "decimal" might sound like a legitimate data type—especially considering that it is used in other programming languages such as SQL—it doesn't exist in PHP. Here, floating-point numbers are used to represent decimal values. Essentially, the float or double data type in PHP can handle decimal numbers.

Handling Decimal Values in PHP

The Float data type in PHP can be used to hold decimals, for example:

$decimal = 10.234;
echo $decimal;

This code declares a variable $decimal and assigns it a decimal value.

Also, if precise operations are needed, functions like bcadd(), bcmul(), etc. are used. They operate as string and allow precision based calculations.

Best Practices

While handling decimal (floating-point) numbers in PHP, it's important to remember that they are not always 100% accurate due to the way they are stored in memory. This tiny precision loss might not be noticeable in general calculations, but when you're dealing with money or other precision-critical values, it's advisable to use PHP's arbitrary precision math functions or the GMP functions.

In conclusion, while "Decimal" might sound like a legitimate PHP data type (especially for those coming from an SQL background), it does not exist in PHP. To handle decimal-like values, PHP offers the Float data type.