<?php
// 浮点数转换
echo 'Convert string to float : ';
var_dump(floatval('12.35'));
echo '<hr>';
echo 'Convert bool to float : ';
var_dump(floatval(true));
echo '<hr>';
echo 'Convert bool to float : ';
var_dump(floatval(false));
echo '<hr>';
echo 'Convert integer to float : ';
var_dump(floatval(12));
echo '<hr>';
// 浮点数比较
$a = 1.23456789;
$b = 1.23456780;
$epsilion1 = 0.00001;
if(abs($a - $b) < $epsilion1) {
echo '$a is equal to $b';
} else {
echo '$a is not equal to $b';
}
echo '<hr>';
$epsilion2 = 0.000000001;
if(abs($a - $b) < $epsilion2) {
echo '$a is equal to $b';
} else {
echo '$a is not equal to $b';
}
echo '<hr>';
/*
结论:浮点数之间的比较不能直接比较,而是需要相对比较
当两个浮点数之差的绝对值小于一个极小值的时候就说明相等
*/
?>
PHP_Day01_数据类型_float
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转载自blog.csdn.net/IronMan240/article/details/83690525
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