PHP high-precision math function library function summary

The PHP language provides a binary calculator (Binary Calculator) for arbitrary precision mathematical calculations, which supports numbers of any size and precision, described in string form.

In php, a high-precision function library is provided: BC high-precision function library. It includes the following calculations: addition, comparison, division, subtraction, remainder, multiplication, nth power, configuring the default number of decimal points, squaring, etc. These functions are useful when calculations involving money are involved.

The following is an introduction to these high-precision functions:

1. bcadd adds two high-precision numbers

The syntax format is as follows:

string bcadd ( string left_operand, string right_operand [, int scale] )

Return value: String

Function type: Mathematical operation

Content description: This function adds two high-precision numbers and passes in two strings , the result is also returned as a string. scale is an optional option that indicates the desired number of digits after the decimal point of the return value.

The following is a code example to demonstrate:

<?php
    $a = 1.0321456;  
    $b = 0.0123456;  
    $c = bcadd($a, $b, 2);  
    //var_dump($c);  
?>

2. bccomp compares two high-precision numbers

The syntax format is as follows:

int bccomp ( string left_operand, string right_operand [, int scale] )

Return value: Integer

Function type: Mathematical operation

Content description: This function compares two high-precision numbers. Input two strings. If the two strings are the same size, 0 will be returned; if the numeric string on the left (left operand) is larger than the numeric string on the right (right operand), +1 will be returned; if the numeric string on the left is smaller than the right one Returns -1. scale is an optional option that indicates the desired number of digits after the decimal point of the return value. To put it simply, $left=$right returns 0 , $left$left>$right returns 1 .

The example code is as follows:

<?php
    $first = &#39;2.2&#39;;
    $second = &#39;13.00&#39;;
    $third = &#39;10.80&#39;;
    $sub = $second - $third;
    echo &#39;$first,$sub两个数相比较：<br/>&#39;;
    echo bccomp($first,$sub,2); echo &#39;<br/>&#39;;
    echo &#39;$first,$second两个数相比较：<br/>&#39;;
    echo bccomp($first,$second,2); echo &#39;<br/>&#39;;
    echo &#39;$second,$third两个数相比较：<br/>&#39;;
    echo bccomp($second,$third,2); echo &#39;<br/>&#39;;
?>

3. bcsub subtracts two high-precision numbers

The syntax format is as follows :

string bcsub ( string left_operand, string right_operand [, int scale] )

Return value: String

Function type: Mathematical operation

Content description: This function subtracts two high-precision numbers and passes in two String, subtract the right operand value from the left operand value. scale is an optional option that indicates the desired number of digits after the decimal point of the return value.

The example code is as follows:

<?php
    $a = 1.0321456;  
    $b = 3.0123456;  
    $c = bcsub($a, $b, 2);  
    var_dump($c);  
?>

4. bcmul multiplies two high-precision numbers

The syntax format is as follows:

string bcmul ( string left_operand, string right_operand [, int scale] )

Return value: String

Function type: Mathematical operation

Content description: This function multiplies two high-precision numbers and passes in two strings. Multiply the left numeric string (left operand) by the right numeric string (right operand). The result is also returned as a string. scale is an optional option that indicates the desired number of digits after the decimal point of the return value. The default number of scale decimal points is 0.

The example code is as follows:

<?php
    $a = 3.1415926;  
    $b = 2.4569874566;  
    $c = bcmul($a, $b, 6);  
    //var_dump($c); 
?>

5. bcdiv divides two high-precision numbers

The syntax format is as follows:

string bcdiv ( string left_operand, string right_operand [, int scale] )

Return value: String

Function type: Mathematical operation

Content description: This function divides two high-precision numbers and passes in two strings. Divide the left numeric string (left operand) by the right numeric string (right operand). The result is also returned as a string. scale is an optional option that indicates the desired number of digits after the decimal point of the return value. The default number of scale decimal points is 0.

The example code is as follows:

<?php
  $a = 6;  
 $b = 5;  
 $c = bcdiv($a, $b, 3);  
 //var_dump($c); 
?>

6. bcmod Get the remainder/modulus of a high-precision number

The syntax format is as follows:

string bcmod ( string left_operand, string modulus )

Return value: String

Function type: Mathematical operation

Content description: Get left operand divided by modulus remainder string.

The example code is as follows:

<?php
    $a = 6;  
    $b = 4;  
    $c = bcmod($a, $b);    
    //var_dump($c);  
?>

7. bcpow Find a high-precision digital power value

The syntax format is as follows:

string bcpow ( string x, string y [, int scale] )

Return value: String

Function type: Mathematical operation

Content description: This function finds the yth power of a high-precision number x. The result is also returned as a string. scale is an optional option that indicates the desired number of digits after the decimal point of the return value. The default number of scale decimal points is 0.

The example code is as follows:

<?php
    $a = 3.1415926;  
    $b = 2;  
    $c = bcpow($a, $b, 3);  
    //var_dump($c);  
?>

8. bcsqrt Find the square root of a high-precision number

The syntax format is as follows:

string bcsqrt ( string operand [, int scale] )

Return value: String

Function type: Mathematical operation

Content description: This function finds the square root of a high-precision number. scale is an optional option that indicates the desired number of digits after the decimal point of the return value. The default number of scale decimal points is 0 .

The example code is as follows:

<?php
    $b = bcsqrt($a, 6);  
    //var_dump($b); 
?>

9. The default number of decimal points for all BC function libraries in the bcscale configuration program

The syntax format is as follows :

 bool bcscale ( int scale )

Return value: boolean

Function type: Mathematical operation

内容说明: 配置所有返回值的小数点后所需的位数。之后程序若无特别指定，则依此配置的小数点位数。

其实例代码如下所示：

<?php
    bcscale(3);
    echo bcdiv(&#39;105&#39;, &#39;6.55957&#39;); // 16.007
?>

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