PHP 類型轉(zhuǎn)換函數(shù)intval
更新時(shí)間:2009年06月20日 00:14:53 作者:
不管什么類型 如果是數(shù)字,就返回?cái)?shù)字,如果不是數(shù)字就返回0
在PHP中用$_GET['id']的時(shí)候就可以這樣來一個(gè)轉(zhuǎn)換...太好了
PHP代碼
$id = intval($_GET['id']);
intval
(PHP 4, PHP 5)
intval — Get the integer value of a variable
Description
int intval ( mixed $var [, int $base= 10 ] )
Returns the integer value of var , using the specified base for the conversion (the default is base 10).
Parameters
var
The scalar value being converted to an integer
base
The base for the conversion (default is base 10)
Return Values
The integer value of var on success, or 0 on failure. Empty arrays and objects return 0, non-empty arrays and objects return 1.
The maximum value depends on the system. 32 bit systems have a maximum signed integer range of -2147483648 to 2147483647. So for example on such a system, intval('1000000000000') will return 2147483647. The maximum signed integer value for 64 bit systems is 9223372036854775807.
Strings will most likely return 0 although this depends on the leftmost characters of the string. The common rules of integer casting apply.
Examples
<?php
echo intval(42); // 42
echo intval(4.2); // 4
echo intval('42'); // 42
echo intval('+42'); // 42
echo intval('-42'); // -42
echo intval(042); // 34
echo intval('042'); // 42
echo intval(1e10); // 1410065408
echo intval('1e10'); // 1
echo intval(0x1A); // 26
echo intval(42000000); // 42000000
echo intval(420000000000000000000); // 0
echo intval('420000000000000000000'); // 2147483647
echo intval(42, 8); // 42
echo intval('42', 8); // 34
?>
$id = intval($_GET['id']);
intval
(PHP 4, PHP 5)
intval — Get the integer value of a variable
Description
int intval ( mixed $var [, int $base= 10 ] )
Returns the integer value of var , using the specified base for the conversion (the default is base 10).
Parameters
var
The scalar value being converted to an integer
base
The base for the conversion (default is base 10)
Return Values
The integer value of var on success, or 0 on failure. Empty arrays and objects return 0, non-empty arrays and objects return 1.
The maximum value depends on the system. 32 bit systems have a maximum signed integer range of -2147483648 to 2147483647. So for example on such a system, intval('1000000000000') will return 2147483647. The maximum signed integer value for 64 bit systems is 9223372036854775807.
Strings will most likely return 0 although this depends on the leftmost characters of the string. The common rules of integer casting apply.
Examples
復(fù)制代碼 代碼如下:
<?php
echo intval(42); // 42
echo intval(4.2); // 4
echo intval('42'); // 42
echo intval('+42'); // 42
echo intval('-42'); // -42
echo intval(042); // 34
echo intval('042'); // 42
echo intval(1e10); // 1410065408
echo intval('1e10'); // 1
echo intval(0x1A); // 26
echo intval(42000000); // 42000000
echo intval(420000000000000000000); // 0
echo intval('420000000000000000000'); // 2147483647
echo intval(42, 8); // 42
echo intval('42', 8); // 34
?>
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