To php dot net at oui dot jp:
It's going to return a string if the variable's value is encased around quotes or apostrophes, period. Be it a '0' or a '1', it's a string all around. The index in an array is a little bit of a different story.
Sample coding is below:
<?php
$ar = array('this is a string.', '38', '038', 0382, 3892.283);
$ar2 = array('S1' => 'string.', 'S2' => 'a string.', '3' => 3827, '3.82.' => '2222', '-1' => 'foo');
foreach($ar as $num => $string)
{
if (is_string($string)) { echo 'Yes. <br />'; } else { echo 'No. <br />'; }
}
print_r($ar);
foreach($ar2 as $num => $string)
{
if (is_string($num)) { echo 'Yes. <br />'; } else { echo 'No. <br />'; }
}
print_r($ar2);
?>
The first foreach contains a simple if/then statement that checks if the array value is a string or not, which works correctly (Yes, Yes, Yes, No, No). The second checks if the index identifier is a string. It returns Yes, Yes, No, and Yes.
Printing the array: Array ( [S1] => string. [S2] => a string. [3] => 3827 [3.82] => 2222 [-1] => foo)
The index identifier will be marked as a string if the identifier is not an integer above zero.
is_string
(PHP 4, PHP 5)
is_string — 変数が文字列かどうかを調べる
説明
bool is_string ( mixed $var )指定した変数が文字列かどうかを調べます。
パラメータ
- var
評価する変数。
返り値
var が string である場合に TRUE、それ以外の場合に FALSE を返します。
参考
| is_float() |
| is_int() |
| is_bool() |
| is_object() |
| is_array() |
is_string
Dainix Zsigmond
02-Aug-2007 12:44
02-Aug-2007 12:44
php dot net at oui dot jp
07-Jun-2007 10:13
07-Jun-2007 10:13
<?php
// Interesting...
$arr = array ('abc','def','ghi');
$aarr = array ('0' => 'abc','1' => 'def','2' => 'ghi');
foreach ($arr as $u => $v)
print is_string($u) ? "Yes\n":"no\n"; // no: ok, index is numeric (0, 1, 2)
foreach ($aarr as $u => $v)
print is_string($u) ? "Yes\n":"no\n"; // still no! was expecting Yes!
if (is_string ('0')) print "'0' is a string\n"; // ...as '0' is a string!
?>
djhook at users dot sourceforge dot net
12-Sep-2003 11:20
12-Sep-2003 11:20
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 10:06
20-Mar-2001 10:06
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.