ctype_cntrl
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.
ctype_digit
(PHP 4 >= 4.0.4, PHP 5)
ctype_digit — Check for numeric character(s)
Description
bool ctype_digit
( string
$text
)
Checks if all of the characters in the provided string,
text, are numerical.
Parameters
-
text -
The tested string.
Return Values
Returns TRUE if every character in the string
text is a decimal digit, FALSE otherwise.
Changelog
| Version | Description |
|---|---|
| 5.1.0 |
Before PHP 5.1.0, this function returned TRUE
when text was an empty string.
|
Examples
Example #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";
}
}
?>
The above example will output:
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.
Example #2 A ctype_digit() example comparing strings with integers
<?php
$numeric_string = '42';
$integer = 42;
ctype_digit($numeric_string); // true
ctype_digit($integer); // false (ASCII 42 is the * character)
is_numeric($numeric_string); // true
is_numeric($integer); // true
?>
Notes
Note:
This function expects a string to be useful, so for example passing in an integer may not return the expected result. However, also note that HTML forms will result in numeric strings and not integers. See also the types section of the manual.
Note:
If an integer between -128 and 255 inclusive is provided, it is interpreted as the ASCII value of a single character (negative values have 256 added in order to allow characters in the Extended ASCII range). Any other integer is interpreted as a string containing the decimal digits of the integer.
See Also
- ctype_alnum() - Check for alphanumeric character(s)
- ctype_xdigit() - Check for character(s) representing a hexadecimal digit
- is_numeric() - Finds whether a variable is a number or a numeric string
- is_int() - Find whether the type of a variable is integer
- is_string() - Find whether the type of a variable is string
add a note
User Contributed Notesctype_digit
robert at mediamonks dot com
12-Jul-2007 10:39
12-Jul-2007 10:39
withheld at withheld dot com
08-Jul-2007 11:06
08-Jul-2007 11:06
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.
robert at mediamonks dot com
04-Jun-2007 11:46
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' :
<?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 09:31
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
07-May-2007 12:09
07-May-2007 12:09
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.