PHP rounding functions

When working with numbers in PHP, rounding becomes essential—whether you’re paginating results or packing boxes. PHP gives us three handy functions for rounding:

1️⃣ floor() – Rounding Down

  • What it does: Always rounds a number down to the nearest whole number.

  • Example:

    $number = 3.7;
$floored = floor($number); // 3
  • When to use it: When you must not exceed a value—e.g., full pages in a document.

2️⃣ ceil() – Rounding Up

  • What it does: Always rounds a number up to the nearest whole number.

  • Example:

    $number = 3.2;
$ceiled = ceil($number); // 4
  • When to use it: When you must not fall short—e.g., counting how many boxes you need to pack items.

3️⃣ round() – Nearest Value Rounding

  • What it does: Rounds to the nearest integer (or decimal precision).

  • How it works:

    • If decimal ≥ 0.5 → rounds up
    • If decimal < 0.5 → rounds down

  • Examples:

    round(3.7); // 4
round(3.2); // 3
round(3.14159, 2); // 3.14
  • When to use it: For general-purpose rounding.

🔎 Summary

  • ✅ Use floor() to always round down
  • ✅ Use ceil() to always round up
  • ✅ Use round() to round to the nearest value

🧠 QUIZ

Question 1: You need to calculate how many boxes are required to pack items, ensuring you don’t run short. 👉 Which PHP function is best and why?

Question 2: What is the output of the following PHP code?

$number = 4.3;
$result = round($number, 0);
echo $result;

💬 Comment your answers below!

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