array ( 0 => 'index.php', 1 => 'PHP Manual', ), 'head' => array ( 0 => 'UTF-8', 1 => 'ja', ), 'this' => array ( 0 => 'function.is-finite.php', 1 => 'is_finite', ), 'up' => array ( 0 => 'ref.math.php', 1 => 'Math 関数', ), 'prev' => array ( 0 => 'function.intdiv.php', 1 => 'intdiv', ), 'next' => array ( 0 => 'function.is-infinite.php', 1 => 'is_infinite', ), 'alternatives' => array ( ), 'source' => array ( 'lang' => 'ja', 'path' => 'reference/math/functions/is-finite.xml', ), ); $setup["toc"] = $TOC; $setup["toc_deprecated"] = $TOC_DEPRECATED; $setup["parents"] = $PARENTS; manual_setup($setup); ?>
(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)
is_finite — 浮動小数点数の値が、有限の数値であるかどうかを調べる
例1 is_finite() の例
<?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));
?>
上の例の出力は以下となります。
float(1.2345) bool(true) float(NAN) bool(false) float(INF) bool(false)