PHP Manual: intval

Description

function intval(mixed $value, int $base = 10): int

Returns the int value of value, using the specified base for the conversion (the default is base 10). intval() should not be used on objects, as doing so will emit an E_WARNING level error and return 1.

Parameters

value

The scalar value being converted to an integer

base

The base for the conversion

Note:
If base is 0, the base used is determined by the format of value:

if string includes a "0x" (or "0X") prefix, the base is taken as 16 (hex); otherwise,

if string starts with a "0b" (or "0B"), the base is taken as 2 (binary); otherwise,

if string starts with "0", the base is taken as 8 (octal); otherwise,

the base is taken as 10 (decimal).

Return Values

The integer value of value on success, or 0 on failure. Empty arrays return 0, non-empty arrays 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.

Note:
Numeric strings using scientific notation (containing the letter e or E) are first parsed as numbers before being converted to an integer.

Because the numeric part of the string is parsed as a whole, the result is not simply the leading integer part. Large exponents can additionally overflow to PHP_INT_MAX:
<?php
echo intval('42.42e42'); // 9223372036854775807 on 64-bit systems
?>
See Numeric strings for details on how such strings are interpreted.

Changelog

Version	Description
8.0.0	The error level when converting from object was changed from `E_NOTICE` to `E_WARNING`.

Examples

Example #1 intval() examples

The following examples are based on a 64 bit system.

<?php
echo intval(42), PHP_EOL;                      // 42
echo intval(4.7), PHP_EOL;                     // 4
echo intval('42'), PHP_EOL;                    // 42
echo intval('+42'), PHP_EOL;                   // 42
echo intval('-42'), PHP_EOL;                   // -42
echo intval(042), PHP_EOL;                     // 34
echo intval('042'), PHP_EOL;                   // 42
echo intval(1e10), PHP_EOL;                    // 10000000000
echo intval('1e10'), PHP_EOL;                  // 10000000000
echo intval(0x1A), PHP_EOL;                    // 26
echo intval('0x1A'), PHP_EOL;                  // 0
echo intval('0x1A', 0), PHP_EOL;               // 26
echo intval('1A', 16), PHP_EOL;                // 26
echo intval(42000000), PHP_EOL;                // 42000000
echo intval(420000000000000000000), PHP_EOL;   // -4275113695319687168
echo intval('420000000000000000000'), PHP_EOL; // 9223372036854775807
echo intval(42, 8), PHP_EOL;                   // 42
echo intval('42', 8), PHP_EOL;                 // 34
echo intval(42, 7), PHP_EOL;                   // 42
echo intval('42', 7), PHP_EOL;                 // 30
echo intval('1000', 11), PHP_EOL;              // 1331
echo intval('1ya', 36), PHP_EOL;               // 2530
echo intval(array()), PHP_EOL;                 // 0
echo intval(array('foo', 'bar')), PHP_EOL;     // 1
echo intval(false), PHP_EOL;                   // 0
echo intval(true), PHP_EOL;                    // 1
?>

Notes

Note:
The base parameter has no effect unless the value parameter is a string.

intval