ctype_space
(PHP 4 >= 4.0.4, PHP 5, PHP 7)
ctype_space — 做空白字符检测
说明
$text
)
检查提供的 string 和 text 里面的字符是否包含空白。
参数
-
text -
需要被测试的字符串。
返回值
如果 text 里面的每个字符最终被实际输出的时候都是某种形式的空白，就返回 TRUE ；否则返回 FALSE 。
除了空白字符，还包括缩进，垂直制表符，换行符，回车和换页字符。
范例
Example #1 一个 ctype_space() 例子
<?php
$strings = array( 'string1' => "\n\r\t" , 'string2' => "\narf12" , 'string3' => '\n\r\t' );
foreach ( $strings as $name => $testcase ) {
if ( ctype_space ( $testcase )) {
echo "The string ' $name ' consists of all whitespace characters.\n" ;
} else {
echo "The string ' $name ' does not consist of all whitespace characters.\n" ;
}
}
?> 以上例程会输出：
The string 'string1' consists of all whitespace characters. The string 'string2' does not consist of all whitespace characters. The string 'string3' does not consist of all whitespace characters.
注释
Note:
如果给出一个 -128 到 255 之间(含)的整数, 将会被解释为该值对应的ASCII字符 (负值将加上 256 以支持扩展ASCII字符). 其它整数将会被解释为该值对应的十进制字符串.
参见
- ctype_cntrl() - 做控制字符检测
- ctype_graph() - 做可打印字符串检测，空格除外
- ctype_punct() - 检测可打印的字符是不是不包含空白、数字和字母
用户评论:
[#1] vlabots at gmail dot com [2014-06-18 07:03:22]
thanks to gardnerjohng, but a had some problems with non-breaking spaces in this function.
I added 2 more cases for this:
case 0xC2
case 0xA0
After this modification non-breaking spaces in my test code were successfully detected.
[#2] gardnerjohng at hotmail dot com [2009-09-14 21:00:01]
A function I wrote last night was fairly flexible in terms of detecting whitespace, and even took into account the pesky non-breaking spaces / zero-width spaces further up the Unicode alphabet.
The benefit here was being able to isolate and identify specific Unicode indices based on their subrange.
<?php
// Returns TRUE if the ASCII value of $string matches a registered whitespace character.
// * This includes non-breaking spaces, zero-width spaces, and any unicode values below 32.
// * $string: Character to identify. If string extends past one character, the value
// is truncated and only the initial character is examined.
function is_whitespace($string){
// Return FALSE if passed an empty string.
if($string == "") return FALSE;
$char = ord($string);
// Control Characters
if($char < 33) return TRUE;
if($char > 8191 && $char < 8208) return TRUE;
if($char > 8231 && $char < 8240) return TRUE;
// Additional Characters
switch($char){
case 160: // Non-Breaking Space
case 8287: // Medium Mathematical Space
return TRUE;
break;
}
return FALSE;
}
?>