PHP pow()函数

pow()是PHP的数学函数。它将第一个数字的值提升到第二个数字的幂次方。

语法

number pow ( number base , numberexp )

返回值：返回一个数字（浮点数和整数），其值等于base的exponent次方。

示例1

<?php
num=pow(3, 2);
echo "Your number is = pow (3, 2)".'<br>';
echo "By using sqrt function Your number is : ".num;
?>

输出：

Your number is =pow(3, 2)
By using sqrt function Your number is : 9

示例2

<?php
num=pow(-4, 2);
echo "Your number is = pow (-4, 2)".'<br>';
echo "By using sqrt function Your number is : ".num;
?>

输出：

Your number is = pow (-4, 2)
By using sqrt function Your number is : 16

示例3

<?php
num=pow(-3, -3);
echo "Your number is =pow(-3, -3)".'<br>';
echo "By using sqrt function Your number is : ".num;
?>

输出:

Your number is =pow(-3, -3)
By using sqrt function Your number is : -0.037037037037037

示例4

<?php
num=pow(-3, -3.2);
echo "Your number is =pow(-3, -3.2)".'<br>';
echo "By using sqrt function Your number is : ".num;
?>

输出：

Your number is =pow(-3, -3.2)
By using sqrt function Your number is : NAN

示例5

<?php
for(i=1;i<=5;i++){
echo "The power value of [i] is". "=".pow($i,2)."<br>";
}
?>

输出：

The power value of [1] is=1
The power value of [2] is=4
The power value of [3] is=9
The power value of [4] is=16
The power value of [5] is=25