PHP: is_string - Manual

downloads | documentation | faq | getting help | mailing lists | reporting bugs | php.net sites | links | conferences | my php.net

search for in the

isset is_scalar

Last updated: Fri, 26 Jan 2007

view this page in

# is_string

(PHP 3, PHP 4, PHP 5)

is_string -- Finds whether a variable is a string

## Описание

bool is_string ( mixed var )

Finds whether the given variable is a string.

## Список параметров

`var`

  The variable being evaluated.

## Возвращаемые значения

Returns `TRUE` if `var` is a string, `FALSE` otherwise.

## Смотрите также

is_float()
is_int()
is_bool()
is_object()
is_array()

add a note User Contributed Notes
is_string
tobias_demuth at web dot de
26-Aug-2005 07:32
`Returns true, if the string is empty, too.`
djhook at users dot sourceforge dot net
11-Sep-2003 07:20
`function is_upper($input) {
return ($input == strtoupper($input));
}
function is_lower($input) {
return ($input == strtolower($input));
}
this functions check if a string is all upper/lower case.
input: string
output: true/false`
slicky at newshelix dot com
20-Mar-2001 05:06
`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.
<p>for ($i=0; $i < strlen($string);$i++){
if(!is_string($key[$x]))
$x = 0;
echo $key[$x];
$x++;
}
</p>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.`
add a note
isset is_scalar

Last updated: Fri, 26 Jan 2007
show source | credits | stats | sitemap | contact | advertising | mirror sites
Copyright © 2001-2007 The PHP Group
All rights reserved.
This mirror generously provided by: Yahoo! Inc.
Last updated: Sat Mar 10 10:36:09 2007 PST