What does round mean in php

In PHP, round means "rounding" and is a built-in function that converts floating point numbers into integers. This function can round floating point numbers and return an integer value of float type. Syntax "round(number,precision,mode);".

The operating environment of this tutorial: windows7 system, PHP8 version, DELL G3 computer

Introduction to php round() function

PHP has two data types for numbers: Integer integer type and Float floating point type. In some special circumstances, we can only use integer types, and for floating point types, we can only convert them to integer types. PHP provides the round() function , can help us accomplish this task.

In PHP, round means "rounding", and its function is to round floating point numbers and return an integer.

Grammar format:

round(number,precision,mode);

Parameters	Description
number	Required. Specifies the value to be rounded.
precision	Optional. Specifies the number of digits after the decimal point. Default is 0, can also be negative.
mode	Optional. Specifies a constant representing the rounding mode: PHP_ROUND_HALF_UP - Default. Round up number to precision decimal places when encountering .5. Rounds 1.5 to 2 and -1.5 to -2. PHP_ROUND_HALF_DOWN - Round down number to precision decimal places when encountering .5. Rounds 1.5 to 1 and -1.5 to -1. PHP_ROUND_HALF_EVEN - When encountering .5, take the next even value and round number to precision decimal places. PHP_ROUND_HALF_ODD - Rounds the next odd value when encountering .5 number to precision decimal places.

Return value: Returns an integer of type float

php round Examples of using the () function

1. Only one parameter:

<?php
header("Content-type:text/html;charset=utf-8");
echo round(6.1)."、";
echo round(6.2)."、";
echo round(6.3)."、";
echo round(6.4)."、";
echo round(6.5)."、";
echo round(6.6)."、";
echo round(6.64)."<br>";
?>

2. There are two parameters:

<?php
header("Content-type:text/html;charset=utf-8");
echo round(6.4545,3)."、";
echo round(6.4545,2)."、";
echo round(6.4545,1)."、";
echo round(6.4545,0)."<br>";
?>

3. Three parameters:

<?php
header("Content-type:text/html;charset=utf-8");
echo round(6.65,1,PHP_ROUND_HALF_DOWN)."<br>";//向下取整
echo round(6.65,1,PHP_ROUND_HALF_UP)."<br>";//向上取整
echo round(6.55,1,PHP_ROUND_HALF_EVEN)."<br>";//遇到 .5 的情况时取下一个偶数值舍入$val到 $precision小数位。
echo round(6.55,1,PHP_ROUND_HALF_ODD)."<br>";//遇到 .5 的情况时取下一个奇数值舍入$val到 $precision小数位。
?>

Extended knowledge: the other two rounding functions

• ceil() function: round up to the nearest integer

• floor() function: round down to the nearest integer

Recommended learning: "PHP Video Tutorial"

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