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ctype_digit

(PHP 4 >= 4.0.4, PHP 5, PHP 7)

ctype_digit — Check for numeric character(s)

Description

ctype_digit ( mixed $text ) : bool

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

Parameters

text

The tested string.

Note:

If an int 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.

Return Values

Returns true if every character in the string text is a decimal digit, false otherwise.

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
?>

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

© 1997–2020 The PHP Documentation Group
Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/function.ctype-digit.php