Method of Rounding Floating Point Numbers by round of Function in PHP

In this paper, an example is given to describe the method of 4 rounding and 5 inputting floating-point numbers by round () function in PHP. Share it for your reference. The specific methods are as follows:

Syntax: round (x, prec)

参数	描述
x	可选,规定要舍入的数字.
prec	可选,规定小数点后的位数.

Description: Returns the result of 4 rounding 5 of x according to the specified precision prec (the number of digits after the decimal point), and prec can also be negative or zero (default value).

Tips and Notes

Note: php does not correctly handle strings like "12,300.2" by default.

Note: The prec parameter was introduced in php 4, and the example code is as follows:

<?php 

*/ 

echo round(3.4);         // Output 3 

echo "<br>"; 

echo round(3.5);         // Output 4 

echo "<br>"; 

echo round(3.6);         // Output 4 

echo "<br>"; 

echo round(3.6,0);         // Output 4 

echo "<br>"; 

echo round(1.95583,2);        // Output 1.96 

echo "<br>"; 

echo round(1241757,-3);        // Output 1242000 

echo "<br>"; 

echo round(4.045,2);         // Output 4.05 

echo "<br>"; 

echo round(4.055,2);         // Output 4.06 

 

// Use stdround Function substitution php Adj. round Function  

?>

<?php 

function   stdround($num,   $d=0)  

{  

      return   round($num   +   0.0001   /   pow(10,   $d),   $d);  

}    

         

echo   "round(1.005,2)= ".round(1.005,2). "n ";  

echo   "round(1.015,2)= ".round(1.015,2). "n ";  

echo   "round(1.025,2)= ".round(1.025,2). "n ";  

echo   "round(1.035,2)= ".round(1.035,2). "n ";  

echo   "round(1.045,2)= ".round(1.045,2). "n ";  

echo   "round(1.055,2)= ".round(1.055,2). "n ";  

echo   "round(1.065,2)= ".round(1.065,2). "n ";  

echo   "round(1.075,2)= ".round(1.075,2). "n ";  

echo   "round(1.085,2)= ".round(1.085,2). "n ";  

echo   "round(1.095,2)= ".round(1.095,2). "n "; 

 

echo   "stdround(1.005,2)= ".stdround(1.005,2). "n ";  

echo   "stdround(1.015,2)= ".stdround(1.015,2). "n ";  

echo   "stdround(1.025,2)= ".stdround(1.025,2). "n ";  

echo   "stdround(1.035,2)= ".stdround(1.035,2). "n ";  

echo   "stdround(1.045,2)= ".stdround(1.045,2). "n ";  

echo   "stdround(1.055,2)= ".stdround(1.055,2). "n ";  

echo   "stdround(1.065,2)= ".stdround(1.065,2). "n ";  

echo   "stdround(1.075,2)= ".stdround(1.075,2). "n ";  

echo   "stdround(1.085,2)= ".stdround(1.085,2). "n ";  

echo   "stdround(1.095,2)= ".stdround(1.095,2). "n "; 

 

$m=0.000000000000001;  

echo   "n ";  

echo   "round(1.005+{$m},2)= ".round(1.005+$m,2). "n ";  

echo   "round(1.015+{$m},2)= ".round(1.015+$m,2). "n ";  

echo   "round(1.025+{$m},2)= ".round(1.025+$m,2). "n ";  

echo   "round(1.035+{$m},2)= ".round(1.035+$m,2). "n ";  

echo   "round(1.045+{$m},2)= ".round(1.045+$m,2). "n ";  

echo   "round(1.055+{$m},2)= ".round(1.055+$m,2). "n ";  

echo   "round(1.065+{$m},2)= ".round(1.065+$m,2). "n ";  

echo   "round(1.075+{$m},2)= ".round(1.075+$m,2). "n ";  

echo   "round(1.085+{$m},2)= ".round(1.085+$m,2). "n ";  

echo   "round(1.095+{$m},2)= ".round(1.095+$m,2). "n "; 

 

echo   "round(1.005,2)= ".round(1.005,2). "n ";  

echo   "round(1.015,2)= ".round(1.015,2). "n ";  

echo   "round(1.025,2)= ".round(1.025,2). "n ";  

echo   "round(1.035,2)= ".round(1.035,2). "n ";  

echo   "round(1.045,2)= ".round(1.045,2). "n ";  

echo   "round(1.055,2)= ".round(1.055,2). "n ";  

echo   "round(1.065,2)= ".round(1.065,2). "n ";  

echo   "round(1.075,2)= ".round(1.075,2). "n ";  

echo   "round(1.085,2)= ".round(1.085,2). "n ";  

echo   "round(1.095,2)= ".round(1.095,2). "n "; 

?>

I hope this article is helpful to everyone's PHP programming.