(PHP 8 >= 8.4.0)
BcMath\Number::sqrt — Gets the square root of an arbitrary precision number
scalescale explicitly specified for calculation results.
If null, the scale of the calculation result will be set automatically.
Returns the square root as a new BcMath\Number object.
When the BcMath\Number::scale of the result object is automatically set,
the BcMath\Number::scale of this object is used. However, in cases such
as indivisible division, the BcMath\Number::scale of the result is expanded.
Expansion is done only as needed, up to a maximum of +10.
That is, if the BcMath\Number::scale of this object is 5,
the BcMath\Number::scale of the result is between 5 and
15.
This method throws a ValueError in the following cases:
scale is outside the valid range示例 #1 BcMath\Number::sqrt() example
<?php
var_dump(
new BcMath\Number('2')->sqrt(),
new BcMath\Number('2')->sqrt(3),
new BcMath\Number('4')->sqrt(),
new BcMath\Number('4')->sqrt(3),
);
?>以上示例会输出：
object(BcMath\Number)#2 (2) {
["value"]=>
string(12) "1.4142135623"
["scale"]=>
int(10)
}
object(BcMath\Number)#3 (2) {
["value"]=>
string(5) "1.414"
["scale"]=>
int(3)
}
object(BcMath\Number)#4 (2) {
["value"]=>
string(1) "2"
["scale"]=>
int(0)
}
object(BcMath\Number)#5 (2) {
["value"]=>
string(5) "2.000"
["scale"]=>
int(3)
}