is_string

(PHP 4, PHP 5)

is_string — 检测变量是否是字符串

描述

bool is_string ( mixed $var )

如果 var 是 string 则返回 TRUE，否则返回 FALSE。

参见 is_bool()、is_int()、is_integer()、is_float()、is_real()、is_object() 和 is_array()。

PHP手册 - N: 检测变量是否是字符串

用户评论:

slicky at newshelix dot com (20-Mar-2001 01:06)

Be aware that this function could result into unwanted results if you check single chars in an array. For instance: You have a simple string and want to repeat this string evertime it ends. <?php for ($i=0; $i < strlen($string);$i++){ if(!is_string($key[$x])) $x = 0; echo $key[$x]; $x++; } ?> This will print you out the key, but won't iterate it since $x won't be reset. is_string function will give out true at element in that string, even if it doesn't exist. for instance is_string $key[1000] while your string is just 10chars long. However this doesn't matter just use $key[$x] == '' instead. Of course you won't use this to iterate a string, but you might come across something where this get useful, for instance for a en/decrypt engine.