IntlChar::digit

(PHP 7)

IntlChar::digit — Get the decimal digit value of a code point for a given radix

说明

public static int IntlChar::digit ( string $codepoint [, int $radix = 10 ] )

Returns the decimal digit value of the code point in the specified radix.

If the radix is not in the range 2<=radix<=36 or if the value of codepoint is not a valid digit in the specified radix, FALSE is returned. A character is a valid digit if at least one of the following is true:

The character has a decimal digit value. Such characters have the general category "Nd" (decimal digit numbers) and a Numeric_Type of Decimal. In this case the value is the character's decimal digit value.
The character is one of the uppercase Latin letters 'A' through 'Z'. In this case the value is c-'A'+10.
The character is one of the lowercase Latin letters 'a' through 'z'. In this case the value is ch-'a'+10.
Latin letters from both the ASCII range (0061..007A, 0041..005A) as well as from the Fullwidth ASCII range (FF41..FF5A, FF21..FF3A) are recognized.

参数

codepoint: The integer codepoint value (e.g. 0x2603 for U+2603 SNOWMAN), or the character encoded as a UTF-8 string (e.g. "\u{2603}")
radix: The radix (defaults to 10).

返回值

Returns the numeric value represented by the character in the specified radix, or FALSE if there is no value or if the value exceeds the radix.

Warning

此函数可能返回布尔值 FALSE，但也可能返回等同于 FALSE 的非布尔值。请阅读布尔类型章节以获取更多信息。应使用 === 运算符来测试此函数的返回值。

范例

Example #1 Testing different code points


<?php
var_dump(IntlChar::digit("0"));
var_dump(IntlChar::digit("3"));
var_dump(IntlChar::digit("A"));
var_dump(IntlChar::digit("A", 16));
?>

以上例程会输出：

int(0)
int(3)
bool(false)
int(10)

参见

IntlChar::forDigit() - Get character representation for a given digit and radix
IntlChar::charDigitValue() - Get the decimal digit value of a decimal digit character
IntlChar::isdigit() - Check if code point is a digit character
IntlChar::PROPERTY_NUMERIC_TYPE