Numerous large and small programs need us to work with numbers. In PHP, numbers can be defined in two different ways. They can be either integers or floats. In addition, strings can be used to express exceedingly huge numbers. 

This PHP guide on round values in PHP will teach you more about these data types and how to convert between them. It is expected that you will need to use one of PHP’s rounding methods, such as ceil(), floor(), or round(), when you want less accuracy than what PHP initially offers.

The number to round is the only parameter that floor() and ceil() need. The rounding function floor() rounds the number to the nearest integer below its current value, and ceil() rounds the number to the nearest integer above its current value. 

Here’s something that will help you understand it better:

Definitions

First, let’s discuss the primary objectives of each function.

Floor (): This function round floats down to the whole number that came before it. For instance, 6.2 becomes 6, and 7.9 becomes 7. 

Ceil (): This function rounds floats up to whole numbers. For instance, 6.2 turns into 7, and 8.9 turns into 9.

Round (): This function yields a float approximately rounded to the given precision, either up or down. If you leave the precision field empty, it will round to the following whole number: 6.2 turns into 6, while 7.9 becomes 8.

Though these functions will, theoretically speaking, return integers, they will still be of the floating point data type. Keep this in mind.

Also Read: Introduction To PHP Language

Which one should I use?

All of the features are helpful in the context that we shall discuss below:

PHP ceil() versus PHP floor()

When dealing with scenarios where using whole numbers is the only option, the floor() and ceil() functions come in handy. Take a look at these two instances:

You must create a program that calculates how many containers are required to deliver some apples to a market. Here, we are constrained by two limitations. To begin with, containers are not fractions. Secondly, we must send every apple. This implies that even if the container is not filled, we will still require a whole one. Thus, we ought to employ ceil().

<?php

$apple_count = 510;

$container_capacity = 50;

$containers_needed = ceil($apple_count/$container_capacity);

echo $containers_needed;

// 11 

?>

Think of another scenario where you need to figure out how many individuals the food will adequately feed. In this instance, you should only extend a greeting to those who you are positive can be served with the food on hand without placing an additional order. The leftover food that is insufficient to feed an adult must be disregarded. Hence, the rounding function floor() needs to be applied.

<?php

$bread_count = 110;

$bread_per_person = 3;

$persons_fed = floor($bread_count/$bread_per_person);

echo $persons_fed;

// 36 

?>

Note: Typecasting converts a floating-point number to an integer faster than the floor() function. The main distinction is that, when dealing with negative values, typecasting would yield -4, whereas floor() will round -4.5 down to -5.

Read Also: Best PHP Libraries Every Developer Should Make Use Of

PHP round()

Unlike ceil() and floor(), which automatically round up or down, the Round Values In PHP (’round()’ function) rounds a number to the nearest integer when no precision is supplied. Three parameters are required:

• The desired rounding number.
• The precision with which the number is rounded—the default value of zero, meaning no digits after the decimal.
• The method used to round halfway numbers is 3.5, -6.5, and 7.5.

Typically, we utilize this function to simplify numbers in daily scenarios when we don’t require absolute precision. In a scientific sense, round() can also be used to eliminate excess accuracy that results from calculations made using data that is more precise than it was.

<?php

    $a = round(7.9); // 8

    $b = round(8.5); // 9

    $c = round(6.4999); // 7

    $d = round(2.123456, 3); // 2.123

    $e = round(2.12345, 4); // 2.1235

    $f = round(1000 / 190); // 5

?>

Conclusion: Round values in PHP

In a nutshell, the round values in pHp come in handy in everyday life when we require an easy-to-remember estimate and don’t care how exact a number turns out to be.

We have just touched on the use of floor(), ceil(), and round() with this quick guide. 

If you want to obtain the next lowest integer, you can use the floor() function; if you want to obtain the next highest integer, you can use the ceil() function.  To round to the nearest integer or non-integer number with the desired accuracy, use the round() function.

I hope this simple guide on Up And Down Round Values In PHP: Ceil, Floor, And Round Functions helped you somehow. Feel free to ask me any questions in the comments, and I will answer them asap.

Also read: What To Look For In A PHP Development Company?

FAQs: Round values in PHP

How does the round() function handle rounding when the decimal part is precisely halfway between two integers?

The round values in PHP uses the “round half to even” strategy, also known as “bankers’ rounding.” If the decimal part is halfway between two integers, it rounds to the closest even number. For example, round(0.5) returns 0, and round(1.5) returns 2.

When can one use the ceil() function instead of round() or floor() in PHP?

You would use the ceil() function when you specifically want to round a number up to the next integer, regardless of the decimal portion. This is useful, for example, when dealing with situations where having a slightly more excellent value is essential, such as when allocating resources.

Is there a function in PHP that always rounds a number to zero?

PHP doesn’t have a built-in function specifically for rounding towards zero. However, you can achieve this by combining floor() and ceil() functions based on the number sign.

How do these rounding functions handle non-numeric values?

If you attempt to use these functions with a non-numeric value, PHP will generate a warning, and the function will return false. It’s vital to ensure the input values are numeric before using these functions to avoid unexpected results.

Is it possible to get specific rounding behaviors by combining these rounding functions?

Yes. These functions can be combined to provide unique rounding behaviors. For example, floor() for positive integers and ceil() for negative values can be used together to round towards zero.