PHP bc Function: High-Precision Math

The bc function in PHP is designed for high-precision calculations, primarily used for performing calculations on floating-point numbers with arbitrary precision.

The syntax of the bc function is as follows:

string bcadd ( string $left_operand , string $right_operand [, int $scale = 0 ] )
string bcsub ( string $left_operand , string $right_operand [, int $scale = 0 ] )
string bcmul ( string $left_operand , string $right_operand [, int $scale = 0 ] )
string bcdiv ( string $left_operand , string $right_operand [, int $scale = 0 ] )
string bcmod ( string $left_operand , string $modulus )
string bcpow ( string $left_operand , string $right_operand [, int $scale = 0 ] )
string bcsqrt ( string $operand [, int $scale = 0 ] )

$left_operand and $right_operand are the two operands to be calculated, they can be in the form of string numbers or BC values. $scale is an optional parameter used to set the number of decimal places in the result, default value is 0.

Here are some examples of using bc functions:

// 加法
$result = bcadd("2.5", "3.7");
echo $result; // 输出：6.2

// 减法
$result = bcsub("5.9", "2.1");
echo $result; // 输出：3.8

// 乘法
$result = bcmul("3.2", "4.5");
echo $result; // 输出：14.4

// 除法
$result = bcdiv("10.5", "2.5");
echo $result; // 输出：4.2

// 求余
$result = bcmod("10", "3");
echo $result; // 输出：1

// 乘方
$result = bcpow("2", "4");
echo $result; // 输出：16

// 开方
$result = bcsqrt("9");
echo $result; // 输出：3

These functions can handle floating-point numbers of any precision and return the calculation result in string form. It is important to note that since string numbers are used, the bc function must be used for calculations instead of regular math operators.