PHP ctype function Chinese translation and examples_PHP tutorial

PHP Ctype extension is a built-in extension since PHP 4.2. Note that the Ctype series functions have only one string type parameter and they return Boolean values.

Copy code The code is as follows:

$str = "0.1123";
//Check whether all characters in the string are For numbers
echo "ctype_digit:" . ctype_digit($str); //Empty
//Detect whether it is a numeric string, which can be negative numbers and decimals
echo "is_numberic:" . is_numeric($str ); //1

You can see the difference between ctype_digit() and is_numberic() from the above.

Chinese translation

The Ctype function is PHP’s built-in string body testing function. There are mainly the following types

ctype_alnum -- Check for alphanumeric character(s)
Check whether it only contains [A-Za-z0-9]

ctype_alpha -- Check for alphabetic character(s)
Check whether it only contains [A-Za-z]

ctype_cntrl -- Check for control character(s)
Check whether it only contains character control characters whose class is "nrt" and so on

ctype_digit -- Check for numeric character(s)
When checking, it is a string containing only numeric characters (0-9)

ctype_graph -- Check for any printable character(s) except space
Check whether it is a string containing only printable characters (except spaces)

ctype_lower -- Check for lowercase character(s)
Check whether all characters are English letters and all are lowercase

ctype_print -- Check for printable character(s)
Check whether it is a string containing only printable characters

ctype_punct -- Check for any printable character which is not whitespace or an alphanumeric character
Check whether it is a printable character that only contains non-digits/characters/spaces

ctype_space -- Check for whitespace character(s)
Check whether it only contains characters and spaces whose class is " " and spaces

ctype_upper -- Check for uppercase character(s)
Check whether all characters are English letters and all are uppercase

ctype_xdigit -- Check for character(s) representing a hexadecimal digit
Check whether it is a hexadecimal string, which can only include "0123456789abcdef"

There are examples

When we usually need to do simple filtering on some forms, we are often reluctant to write regular expressions. In terms of efficiency, regular expressions are also one of the reasons that affect the running speed of PHP, so try to use regular expressions when you can. Don't try regular rules. Fortunately, PHP has taken this into account for us and provided me with Ctype functions. Here is a brief introduction to some Ctype functions for reference:
1. ctype_alnum — Check for alphanumeric character(s) Check that the string only contains numbers or letters, which is equivalent to regular [A-Za-z0-9] . has a return value. Returns TRUE on success, FALSE on failure;
[

Copy code The code is as follows:

$ strings = array('AbCd1zyZ9', 'foo!#$bar');
foreach ($strings as $testcase) {
if (ctype_alnum($testcase)) {
echo "The string $testcase \ Output The string foo!#$bar does not consist of all letters or digits.
}
}
?>
2. ctype_alpha — Check for alphabetic character(s)　Check that the string only contains letters. Returns TRUE on success, FALSE on failure;

Copy code

The code is as follows:

$strings = array('KjgWZC', 'arf12'); foreach ($strings as $testcase) {

if (ctype_alpha($testcase)) {

echo "The string $testcase consists of all letters. n"; \ output The string KjgWZC consists of all letters.
} else {
} echo "The string $testcase does not consist of all letters.n"; \ Output The string arf12 does not consist of all letters.
}
}
?>



3. ctype_cntrl — Check for control character(s)　 Check whether the string only contains control characters such as " 'n' 'r' 't' ".

Copy code

The code is as follows:

$strings = array('string1' => "nrt", 'string2' => 'arf12'); 
foreach ($strings as $name => $testcase) { 
    if (ctype_cntrl($testcase)) { 
        echo "The string '$name' consists of all control characters.n"; \ 输出 The string 'string1' consists of all control characters. 
    } else { 
        echo "The string '$name' does not consist of all control characters.n"; \ The string 'string2' does not consist of all control characters. 
    } 
} 
?>  

4、ctype_digit — Check for numeric character(s)　检查字符串中是否只包含数字

复制代码 代码如下:

$strings = array('1820.20', '10002', 'wsl!12'); 
foreach ($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"; 
    } 
} 
?>  

http://www.bkjia.com/PHPjc/744329.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/744329.htmlTechArticlePHP Ctype扩展是PHP4.2开始就内建的扩展，注意，Ctype系列函数都只有一个字符串类型参数，它们返回布尔值。 复制代码 代码如下: $str = "0.11...