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ctype_digit

(PHP 4 >= 4.0.4, PHP 5)

ctype_digit -- Check for numeric character(s)

说明

bool ctype_digit ( string text )

Checks if all of the characters in the provided string, text, are numerical.

参数

text

The tested string.

返回值

Returns TRUE if every character in text is a decimal digit, FALSE otherwise.

范例

例 1. A ctype_digit() example

<?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";
    }
}
?>

上例将输出：

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.

参见

ctype_alnum()
ctype_xdigit()


add a note add a note User Contributed Notes
robert at mediamonks dot com
12-Jul-2007 08:39
withheld at withheld dot com:
it is called : 'User Contributed Notes' not 'Bugs' so I am not saying there is something wrong with the function at all.

It is used for tips, tricks and simple mistakes people could make using the function. I just noted something just like that, nothing wrong with that.
withheld at withheld dot com
08-Jul-2007 09:06
robert at mediamonks dot com writes...

04-Jun-2007 11:46
I always used this function to check user input but it failed me when I wanted to check int's used in my script. This is caused by the fact that the function only functions right when the argument is a string. Here is a solution for this 'problem' :

Could we have some accuracy in these comments please? If the spec at the top of this page is taken to be correct then Robert is incorrect as it clearly states that the argument should be a string. Skimming notes in this section suggests to the reader that there is a problem with this function when actually people just arent reading the documentation - proliferation of careless mistakes.
jengelh@
12-Jun-2007 06:24
ctype_digit("") returns false in PHP5.
robert at mediamonks dot com
04-Jun-2007 09:46
I always used this function to check user input but it failed me when I wanted to check int's used in my script. This is caused by the fact that the function only functions right when the argument is a string. Here is a solution for this 'problem' :

<?php
$intCheckThis = 99;

$blnResult = ctype_digit($intCheckThis); // returns FALSE

$blnResult = ctype_digit(strval($intCheckThis)); // returns TRUE
?>

Note that user input from form or request uri is always handled as string anyway.
15-May-2007 07:31
You have your if() statement backwards. It's returning "This does not consist of only digits." when cytype_digit($var) is true.

<?php
$var = 5;
if (cytype_digit($var))
{
   echo "This does not consist of only digits.";
}
else
{
   echo "This cosists of only digits.";
}
?>
shivanfalcon at gmail dot com
06-May-2007 10:09
This function also seems to give a false for integers (PHP 4.4.4)
<?php
$var = 5;
if (cytype_digit($var))
{
   echo "This does not consist of only digits.";
}
else
{
   echo "This cosists of only digits.";
}
?>
Returns "This does not consist of only digits.".
I can only assume that this is because of how integers are seen.
2 = 00000010 bitwise
bitwise, 00000010 happens to be some ASCII formatting character, which isn't a digit.
reuvenab at gmail dot com
05-Apr-2007 09:44
Just be aware that
ctype_digit('') == 1
add a note add a note


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