PHP代码

$id = intval($_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

复制代码 代码如下:

<?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

?>