Numeric Operations in PHP

From the basics of numeric types in PHP to operators, rounding, bitwise operations, formatting, and conversions, this guide explains everything in an easy-to-understand manner for beginners.

What Numeric Types Can Be Used in PHP? Differences Between Integers and Floating-Point Numbers

PHP mainly handles the following two types of numeric values. Being aware of types can help prevent unexpected errors and accuracy issues.

• Integer (int): Numbers without a decimal point
• Floating-point (float or double): Numbers with a decimal point

Basic Functions for Type Checking and Conversion with Examples

<?php
$int = 100; // Integer
$float = 3.14; // Floating-point number

echo gettype($int); // Output: integer
echo gettype($float); // Output: double
?>

List of Arithmetic Operators in PHP and Their Basic Usage

By using arithmetic operators in PHP, you can perform basic calculations such as addition, subtraction, multiplication, division, and modulus.

<?php
$a = 10;
$b = 3;

echo $a + $b;  // 13
echo "\n";

echo $a - $b;  // 7
echo "\n";

echo $a * $b;  // 30
echo "\n";

echo $a / $b;  // 3.3333333333333
echo "\n";

echo $a % $b;  // 1
echo "\n";

echo $a ** $b; // 10 to the power of 3 = 1000
?>

Basics of Bitwise Operators: How to Use AND, OR, XOR, and Bit Shifts

Bitwise operators perform operations by treating numbers as binary values. Although not frequently used, they can be helpful for efficient flag management and performance optimization.

<?php
$a = 6;  // 110
$b = 3;  // 011

echo $a & $b; // 2 (binary: 010)
?>

Rounding Numbers: How to Floor, Ceil, and Round in PHP

PHP provides functions for handling decimal rounding.

<?php
$num = 3.75;

echo floor($num); // 3: Round down
echo ceil($num);  // 4: Round up
echo round($num); // 4: Round to nearest
?>

Number Formatting: How to Add Separators and Format Decimals

When displaying numbers, formatting them in a readable way is important. The number_format() function allows you to neatly output currency or statistical values.

<?php
$price = 1234567.89;

echo number_format($price); // 1,234,568
echo number_format($price, 2); // 1,234,567.89
?>

How to Use Functions to Generate Random Numbers

PHP provides several functions to generate random numbers.

<?php
echo rand(1, 100);       // Random integer between 1 and 100
echo mt_rand(1, 1000);   // Faster random integer generation
?>

If you need cryptographically secure random numbers, use random_int() (available from PHP 7).

<?php
echo random_int(1, 10); // Secure random number
?>

Conversion Between Numbers and Strings, and Summary of Number Handling Functions

In PHP, you can convert between numbers and strings, but be careful of unintended type conversions.

<?php
$str = "100px";
$num1 = (int)$str;          // 100
$num2 = intval($str);       // 100
$flt  = (float)"3.14abc";   // 3.14
$s    = strval(123.45);     // "123.45"

var_dump($num1, $num2, $flt, $s);
?>

<?php
$price = 9876543.21;
echo number_format($price);         // 9,876,543
echo "\n";
echo number_format($price, 1);      // 9,876,543.2

echo sprintf("Balance is %.2f yen", 1234.5);
// Output: Balance is 1234.50 yen
?>

<?php
echo abs(-10), "\n";        // 10
echo round(2.71828, 2), "\n"; // 2.72
echo ceil(4.2), "\n";        // 5
echo floor(4.8), "\n";       // 4
echo max(3, 7, 2), "\n";     // 7
echo min(3, 7, 2), "\n";     // 2
echo pow(3, 4), "\n";        // 81
echo sqrt(81), "\n";         // 9
echo rand(1, 10), "\n";      // e.g. 4
?>

Summary

Numeric operations in PHP are essential in many aspects of web development.
This article has covered everything from basic numeric types to operators, rounding, bitwise operations, formatting, random number generation, and type conversion.
For beginners, we recommend deepening your understanding by writing and experimenting with actual code.