Numbers in PHP
PHP supports various numeric data types and provides built-in functions for performing mathematical operations, conversions, and formatting.
1. Numeric Data Types in PHP
PHP has three main types of numbers:
- Integer (int) – Whole numbers (positive or negative).
- Floating-Point (float or double) – Decimal numbers.
- Number Strings – Strings containing numeric values (can be converted).
2. Integer (int)
An integer is a whole number without decimals, within the range:
- 32-bit system: -2,147,483,648 to 2,147,483,647
- 64-bit system: -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
Declaring an Integer
<?php
$num1 = 100;
$num2 = -50;
echo $num1; // Output: 100
?>
Checking if a Value is an Integer (is_int())
<?php
var_dump(is_int(100)); // Output: bool(true)
var_dump(is_int(10.5)); // Output: bool(false)
?>
3. Floating-Point (float or double)
A floating-point number is a number with a decimal point or in exponential form.
Declaring a Float
<?php
$price = 9.99;
$scientific = 5.1e3; // 5.1 × 10^3 = 5100
?>
Checking if a Value is a Float (is_float())
<?php
var_dump(is_float(10.5)); // Output: bool(true)
?>
Using Exponential Notation
<?php
$num = 2e3; // Equivalent to 2000
echo $num; // Output: 2000
?>
4. Numeric Strings
A numeric string is a string that contains a valid number.
Checking if a String is Numeric (is_numeric())
<?php
var_dump(is_numeric(“123”)); // Output: bool(true)
var_dump(is_numeric(“123.45”)); // Output: bool(true)
var_dump(is_numeric(“Hello”)); // Output: bool(false)
?>
Converting a Numeric String to a Number
PHP automatically converts numeric strings during mathematical operations.
<?php
$x = “10”;
$y = $x + 5;
echo $y; // Output: 15
?>
5. Arithmetic Operations in PHP
PHP supports standard arithmetic operations:
| Operator | Description | Example |
| + | Addition | $a + $b |
| – | Subtraction | $a – $b |
| * | Multiplication | $a * $b |
| / | Division | $a / $b |
| % | Modulus (Remainder) | $a % $b |
| ** | Exponentiation | $a ** $b |
Examples of Arithmetic Operations
<?php
$a = 10;
$b = 3;
echo $a + $b; // Output: 13
echo $a – $b; // Output: 7
echo $a * $b; // Output: 30
echo $a / $b; // Output: 3.3333
echo $a % $b; // Output: 1
echo $a ** $b; // Output: 1000 (10^3)
?>
6. Rounding and Formatting Numbers
6.1 Rounding a Number (round())
<?php
echo round(3.6); // Output: 4
echo round(3.2); // Output: 3
?>
6.2 Rounding Up (ceil())
<?php
echo ceil(3.2); // Output: 4
?>
6.3 Rounding Down (floor())
<?php
echo floor(3.8); // Output: 3
?>
6.4 Formatting a Number (number_format())
<?php
$number = 1234.5678;
echo number_format($number, 2); // Output: 1,234.57
?>
7. Random Numbers
PHP provides functions to generate random numbers.
7.1 Generating a Random Number (rand())
<?php
echo rand(); // Outputs a random number
?>
7.2 Generating a Random Number within a Range
<?php
echo rand(1, 100); // Outputs a random number between 1 and 100
?>
7.3 Generating a Cryptographically Secure Random Number (random_int())
<?php
echo random_int(1, 100); // Outputs a secure random number between 1 and 100
?>
8. Mathematical Functions
PHP provides built-in math functions.
8.1 Absolute Value (abs())
<?php
echo abs(-10); // Output: 10
?>
8.2 Square Root (sqrt())
<?php
echo sqrt(16); // Output: 4
?>
8.3 Power (pow())
<?php
echo pow(2, 3); // Output: 8 (2^3)
?>
8.4 Logarithm (log())
<?php
echo log(10); // Natural logarithm (base e)
?>
8.5 Trigonometric Functions (sin(), cos(), tan())
<?php
echo sin(M_PI / 2); // Output: 1
?>
9. Type Conversion
PHP allows explicit conversion of numbers.
9.1 Casting to Integer ((int))
<?php
$num = 10.99;
$intNum = (int) $num;
echo $intNum; // Output: 10
?>
9.2 Casting to Float ((float))
<?php
$num = “10.5”;
$floatNum = (float) $num;
echo $floatNum; // Output: 10.5
?>
9.3 Converting a Number to a String (strval())
<?php
$num = 123;
$str = strval($num);
echo gettype($str); // Output: string
?>
10. Checking for Finite and Infinite Numbers
10.1 Checking for Infinity (is_infinite())
<?php
$num = 1.9e308;
var_dump(is_infinite($num)); // Output: bool(true)
?>
10.2 Checking for NaN (is_nan())
<?php
var_dump(is_nan(acos(2))); // Output: bool(true) (invalid mathematical operation)
?>
11. Conclusion
- PHP supports integers, floats, and numeric strings.
- PHP provides arithmetic operations like +, -, *, /, %, and **.
- PHP has math functions for rounding (round(), ceil(), floor()), random number generation (rand(), random_int()), and advanced calculations (pow(), sqrt(), log()).
- PHP can convert numbers to different types explicitly.
Understanding numbers in PHP is essential for performing calculations, handling user input, and processing financial data efficiently.