PHP Numbers

PHP is a popular server-side programming language that is commonly used for web development. One of the most important data types in PHP is numbers, which are used to represent numerical values such as integers, floating-point numbers, and scientific notation.

In PHP, integers are whole numbers without any decimal places. They can be positive or negative, and there is no limit to the size of an integer that can be stored. For example, the integer 10 is represented as 10 in PHP, while the integer -10 is represented as -10.

Floating-point numbers, also known as decimal numbers, are numbers with decimal places. They can also be positive or negative and can have a fractional part. For example, the floating-point number 3.14 is represented as 3.14 in PHP.

PHP also supports scientific notation, which is a way of writing very large or very small numbers using powers of 10. For example, the number 1,000,000 can be written as 1E6 in scientific notation.

In PHP, numbers can be used in a variety of ways. They can be used for arithmetic operations, such as addition, subtraction, multiplication, and division. They can also be used for comparison operations, such as greater than, less than, and equal to.

One important feature of PHP numbers is their type. PHP distinguishes between different types of numbers, such as integers and floating-point numbers, and automatically converts between them as needed. For example, if you add an integer and a floating-point number, PHP will automatically convert the integer to a floating-point number before performing the addition.

Read More:- PHP Strings

Another important feature of PHP numbers is their precision. Because floating-point numbers are stored in binary form, they can sometimes have rounding errors when performing arithmetic operations. To avoid these errors, PHP provides a number of functions for performing precise calculations, such as the bcmath extension.

In conclusion, PHP numbers are an essential part of web development, and understanding their properties and features is crucial for writing effective PHP code. Whether you're working with integers, floating-point numbers, or scientific notation, PHP provides a powerful set of tools for working with numerical data.

One thing to notice about PHP is that it provides automatic data type conversion.

So, if you assign an integer value to a variable, the type of that variable will automatically be an integer. Then, if you assign a string to the same variable, the type will change to a string.

This automatic conversion can sometimes break your code.

PHP Integers
Integers are a data type used to represent whole numbers without any decimal places. They can be positive or negative, and there is no limit to the size of an integer that can be stored. This makes integers a powerful data type that can be used in a wide variety of applications.

One of the key features of PHP integers is their size. Unlike other programming languages that have fixed-size integers, PHP supports arbitrarily large integers, which means you can use integers of any size. This makes PHP a popular choice for applications that deal with large numbers, such as cryptography, scientific computing, and financial calculations.

PHP integers are also versatile and can be used in a wide variety of operations. They can be used for basic arithmetic operations, such as addition, subtraction, multiplication, and division. They can also be used in comparison operations, such as greater than, less than, and equal to.

Another important feature of PHP integers is their type. PHP distinguishes between different types of integers, such as signed integers and unsigned integers, and automatically converts between them as needed. This makes it easy to work with different types of integers in the same application without having to worry about type conversions.

PHP integers are also easy to manipulate and format. For example, you can use the number_format() function to format an integer with commas as thousands separators or the sprintf() function to format an integer as a string with a specific number of decimal places.

Finally, PHP integers are supported by a wide range of libraries and extensions that can be used to extend their functionality. For example, the GMP extension provides functions for working with large integers, while the BC Math extension provides functions for performing precise calculations with floating-point numbers.

In conclusion, PHP integers are a versatile and powerful data type that can be used in a wide variety of applications. Their arbitrary size, automatic type conversion, and ease of manipulation and formatting make them an essential tool for web developers working with numerical data.

2, 256, -256, 10358, -179567 are all integers.

An integer is a number without any decimal part.

An integer data type is a non-decimal number between -2147483648 and 2147483647 in 32 bit systems, and between -9223372036854775808 and 9223372036854775807 in 64 bit systems. A value greater (or lower) than this, will be stored as float, because it exceeds the limit of an integer.

Note: Another important thing to know is that even if 4 * 2.5 is 10, the result is stored as float, because one of the operands is a float (2.5).

Here are some rules for integers:

• An integer must have at least one digit
• An integer must NOT have a decimal point
• An integer can be either positive or negative
• Integers can be specified in three formats: decimal (10-based), hexadecimal (16-based - prefixed with 0x) or octal (8-based - prefixed with 0)

PHP has the following predefined constants for integers:

• PHP_INT_MAX - The largest integer supported
• PHP_INT_MIN - The smallest integer supported
• PHP_INT_SIZE - The size of an integer in bytes

PHP has the following functions to check if the type of a variable is integer:

• is_int()
• is_integer() - alias of is_int()
• is_long() - alias of is_int()

Example
Check if the type of a variable is integer:



PHP Floats
A float is a number with a decimal point or a number in exponential form.

2.0, 256.4, 10.358, 7.64E+5, 5.56E-5 are all floats.

The float data type can commonly store a value up to 1.7976931348623E+308 (platform dependent), and have a maximum precision of 14 digits.

PHP has the following predefined constants for floats (from PHP 7.2):

• PHP_FLOAT_MAX - The largest representable floating point number
• PHP_FLOAT_MIN - The smallest representable positive floating point number
• PHP_FLOAT_MAX - The smallest representable negative floating point number
• PHP_FLOAT_DIG - The number of decimal digits that can be rounded into a float and back without precision loss
• PHP_FLOAT_EPSILON - The smallest representable positive number x, so that x + 1.0 != 1.0

PHP has the following functions to check if the type of a variable is float:

• is_float()
• is_double() - alias of is_float()

PHP Infinity
A numeric value that is larger than PHP_FLOAT_MAX is considered infinite.

PHP has the following functions to check if a numeric value is finite or infinite:

• is_finite()
• is_infinite()

However, the PHP var_dump() function returns the data type and value:



PHP NaN
NaN stands for Not a Number.

NaN is used for impossible mathematical operations.

PHP has the following functions to check if a value is not a number:

• is_nan()

However, the PHP var_dump() function returns the data type and value:



PHP Numerical Strings
The PHP is_numeric() function can be used to find whether a variable is numeric. The function returns true if the variable is a number or a numeric string, false otherwise.



PHP Casting Strings and Floats to Integers
Sometimes you need to cast a numerical value into another data type.

The (int), (integer), or intval() function are often used to convert a value to an integer.