PHP Numbers
Working with numeric data in PHP
🔢 What are Numbers?
PHP supports integers and floating-point numbers for mathematical operations. Numbers can be positive, negative, or zero and are essential for calculations, counting, and data processing in programs.
<?php
$integer = 42; // Whole number
$float = 3.14; // Decimal number
$negative = -10; // Negative number
echo "Integer: $integer<br>";
echo "Float: $float";
?>
Output:
Integer: 42
Float: 3.14
Number Types
Integers
Whole numbers without decimal points. Can be positive, negative, or zero for counting and indexing operations.
<?php
$age = 25;
$year = 2024;
$temp = -5;
?>Floats
Numbers with decimal points for precise calculations. Also called doubles, used for measurements and financial data.
<?php
$price = 19.99;
$pi = 3.14159;
$rate = 0.05;
?>Scientific
Numbers in exponential notation for very large or small values using 'e' notation for scientific calculations.
<?php
$large = 2.5e6; // 2500000
$small = 1.5e-3; // 0.0015
?>Infinity
Special numeric values representing infinite numbers. PHP has constants for positive and negative infinity values.
<?php
$inf = INF;
$negInf = -INF;
echo is_infinite($inf);
?>🔹 Integer Numbers
Working with whole numbers:
<?php
// Positive integer
$positive = 100;
// Negative integer
$negative = -50;
// Zero
$zero = 0;
// Check if integer
echo "Is $positive an integer? ";
echo is_int($positive) ? "Yes" : "No";
echo "<br>";
// Integer operations
$sum = $positive + $negative;
echo "Sum: $sum<br>";
$product = $positive * 2;
echo "Product: $product";
?>Output:
Is 100 an integer? Yes
Sum: 50
Product: 200
🔹 Float Numbers
Working with decimal numbers:
<?php
// Float numbers
$price = 29.99;
$pi = 3.14159;
$rate = 0.075;
// Check if float
echo "Is $price a float? ";
echo is_float($price) ? "Yes" : "No";
echo "<br>";
// Float operations
$total = $price * 2;
echo "Total: $" . number_format($total, 2) . "<br>";
// Rounding
$rounded = round($pi, 2);
echo "Pi rounded: $rounded";
?>Output:
Is 29.99 a float? Yes
Total: $59.98
Pi rounded: 3.14
🔹 Number Checking Functions
Verify number types and properties:
<?php
$int = 42;
$float = 3.14;
$string = "123";
// Check if numeric
echo "Is '$string' numeric? ";
echo is_numeric($string) ? "Yes" : "No";
echo "<br>";
// Check if integer
echo "Is $int an integer? ";
echo is_int($int) ? "Yes" : "No";
echo "<br>";
// Check if float
echo "Is $float a float? ";
echo is_float($float) ? "Yes" : "No";
echo "<br>";
// Check if finite
echo "Is $int finite? ";
echo is_finite($int) ? "Yes" : "No";
?>Output:
Is '123' numeric? Yes
Is 42 an integer? Yes
Is 3.14 a float? Yes
Is 42 finite? Yes
🔹 Number Formatting
Format numbers for display:
<?php
$number = 1234567.89;
// Format with commas
echo number_format($number) . "<br>";
// Format with 2 decimals
echo number_format($number, 2) . "<br>";
// Custom formatting
echo number_format($number, 2, ".", ",") . "<br>";
// Currency formatting
$price = 1234.56;
echo "$" . number_format($price, 2);
?>Output:
1,234,568
1,234,567.89
1,234,567.89
$1,234.56
🔹 Rounding Numbers
Round numbers to specific precision:
<?php
$number = 3.14159;
// Round to nearest integer
echo "round(): " . round($number) . "<br>";
// Round to 2 decimals
echo "round(2): " . round($number, 2) . "<br>";
// Round up
echo "ceil(): " . ceil($number) . "<br>";
// Round down
echo "floor(): " . floor($number) . "<br>";
// Absolute value
$negative = -5.5;
echo "abs(): " . abs($negative);
?>Output:
round(): 3
round(2): 3.14
ceil(): 4
floor(): 3
abs(): 5.5
🔹 Random Numbers
Generate random numbers:
<?php
// Random integer between 1 and 10
$random1 = rand(1, 10);
echo "Random (1-10): $random1<br>";
// Random integer between 1 and 100
$random2 = rand(1, 100);
echo "Random (1-100): $random2<br>";
// Better random number
$random3 = mt_rand(1, 10);
echo "MT Random (1-10): $random3<br>";
// Random float between 0 and 1
$randomFloat = mt_rand() / mt_getrandmax();
echo "Random float: " . round($randomFloat, 2);
?>Output:
Random (1-10): 7
Random (1-100): 42
MT Random (1-10): 3
Random float: 0.65