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(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)
is_finite — 判断浮点数是否是有效的有限值
示例 #1 is_finite() 示例
<?php
$float = 1.2345;
var_dump($float, is_finite($float));
$nan = sqrt(-1);
var_dump($nan, is_finite($nan));
$inf = 1e308 * 2;
var_dump($inf, is_finite($inf));
?>
以上示例会输出:
float(1.2345) bool(true) float(NAN) bool(false) float(INF) bool(false)