PHP Numbers: Working with Integers and Floats in PHP

Numbers are a data type used for mathematical calculations and numerical data processing. PHP supports different types of numbers, such as integers, floating-point numbers (floats), and provides a wide range of functions to perform mathematical operations.

Types of Numbers in PHP

Integers
Floats (Floating-Point Numbers or Doubles)
Number Strings

PHP has two more data types

Infinity
NaN

PHP Integers

Integers are whole numbers, without a decimal point.
They can be positive, negative, or zero.

Range of an Integer:

On a 32-bit system, integers typically range from -2,147,483,648 to 2,147,483,647.

On a 64-bit system, the range is -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807.

Integer values can be represented in different bases:

Decimal (Base 10): 123

Hexadecimal (Base 16): Prefixed with 0x (e.g., 0x1A)

Octal (Base 8): Prefixed with 0 (e.g., 0123)

Binary (Base 2): Prefixed with 0b (e.g., 0b1010)

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

is_int() , is_integer() , is_long() functions to check if the type of a variable is integer.

Example

<!DOCTYPE html>

<html>

<body>

<?php

$value = 10;

echo is_int($value) ? "Yes " : "No "; // Outputs: Yes

$x = 4356;

var_dump(is_int($x));

echo " ";

$x = 43.56;

var_dump(is_long($x));

</body>

</html>

Try it yourself

PHP Floats (Floating-Point Numbers)

Floats are numbers with a decimal point or in exponential form (e.g., 1.5e3).
Useful for representing fractional values or numbers with a precision.

Predefined Constants for integers

PHP_FLOAT_MAX - The largest representable floating point number
PHP_FLOAT_MIN - The smallest representable positive 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

is_float(), is_double() functions to check if the type of a variable is float.

Example

<!DOCTYPE html>

<html>

<body>

<?php

$x = 4356;

var_dump(is_float($x));

echo " ";

$x = 43.56;

var_dump(is_double($x));

</body>

</html>

Try it yourself

PHP Numerical Strings

Numerical strings are strings that contain numbers and can be treated as numbers in certain situations. When a string contains a numeric value (either integer or floating-point), PHP can automatically treat it as a number when used in arithmetic operations or comparisons.

Example

<!DOCTYPE html>

<html>

<body>

<?php

$numString = "42";

$sum = $numString + 8; // Converts "42" to an integer and performs addition

echo $sum; // Outputs: 50

var_dump(is_numeric($numString));

$x = "Hello";

var_dump(is_numeric($x));

</body>

</html>

Try it yourself

PHP Infinity

Infinity is a special value that represents a number beyond the range that can be represented by a float. It is denoted by the constant INF for positive infinity and -INF for negative infinity.

How to Work with Infinity in PHP

Generating Infinity:

You can generate positive infinity using division by zero for floats or by using a number larger than PHP_FLOAT_MAX.
Negative infinity is produced by dividing a negative number by zero or using a number smaller than -PHP_FLOAT_MAX.

is_finite(), is_infinite() functions to check if a numeric value is finite or infinite.

Example

<!DOCTYPE html>

<html>

<body>

<?php

// Positive infinity

$positiveInfinity = 1.0 / 0; // Outputs: INF

$positiveInfinityAlt = PHP_FLOAT_MAX * 2; // Outputs: INF

// Negative infinity

$negativeInfinity = -1.0 / 0; // Outputs: -INF

$negativeInfinityAlt = -PHP_FLOAT_MAX * 2; // Outputs: -INF

echo $positiveInfinity; // Displays: INF

echo $negativeInfinity; // Displays: -INF

</body>

</html>

Try it yourself

PHP NaN

NAN (Not A Number) is a special floating-point value that represents the result of an undefined or unrepresentable mathematical operation.

For example, operations like taking the square root of a negative number or dividing zero by zero can produce a NaN result.

To check if a value is NaN, you can use the is_nan() function. This function returns true if the value is NAN, otherwise false.

Example

<!DOCTYPE html>

<html>

<body>

<?php

// Invalid calculation will return a NaN value

$x = sqrt(-8);

var_dump($x);

</body>

</html>

PHP Casting Strings (Type casting)

PHP offers various ways to cast a numerical value into another data type.

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

Example

<!DOCTYPE html>

<html>

<body>

<?php

$str = "123.45";

$intValue = (int)$str; // Converts to integer (123)

$floatValue = (float)$str; // Converts to float (123.45)

echo $intValue." ";

echo $floatValue;

</body>

</html>

Try it yourself

❮ Previous

Next ❯

Whereisstuff is simple learing platform for beginer to advance level to improve there skills in technologies.we will provide all material free of cost.you can write a code in runkit workspace and we provide some extrac features also, you agree to have read and accepted our terms of use, cookie and privacy policy.