(PHP 4, PHP 5, PHP 7, PHP 8)
is_numeric — 檢測(cè)變量是否為數(shù)字或數(shù)字字符串
value
需要檢測(cè)的變量。
如果 value
是數(shù)字或數(shù)字字符串,
返回 true
;否則返回 false
。
示例 #1 is_numeric() 示例
<?php
$tests = array(
"42",
1337,
0x539,
02471,
0b10100111001,
1337e0,
"0x539",
"02471",
"0b10100111001",
"1337e0",
"not numeric",
array(),
9.1,
null,
'',
);
foreach ($tests as $element) {
if (is_numeric($element)) {
echo var_export($element, true) . " is numeric", PHP_EOL;
} else {
echo var_export($element, true) . " is NOT numeric", PHP_EOL;
}
}
?>
以上例程會(huì)輸出:
'42' is numeric 1337 is numeric 1337 is numeric 1337 is numeric 1337 is numeric 1337.0 is numeric '0x539' is NOT numeric '02471' is numeric '0b10100111001' is NOT numeric '1337e0' is numeric 'not numeric' is NOT numeric array ( ) is NOT numeric 9.1 is numeric NULL is NOT numeric '' is NOT numeric