(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)
ctype_digit — 检测数字字符
示例 #1 ctype_digit() 示例
<?php
$strings = array('1820.20', '10002', 'wsl!12');
foreach ($strings as $testcase) {
if (ctype_digit($testcase)) {
echo "The string $testcase consists of all digits.\n";
} else {
echo "The string $testcase does not consist of all digits.\n";
}
}
?>以上示例会输出：
The string 1820.20 does not consist of all digits. The string 10002 consists of all digits. The string wsl!12 does not consist of all digits.
示例 #2 ctype_digit() 示例，比对字符和整数
<?php
$numeric_string = '42';
$integer = 42;
ctype_digit($numeric_string); // true
ctype_digit($integer); // false（ASCII 42 是 * 字符）
is_numeric($numeric_string); // true
is_numeric($integer); // true
?>