IntlChar::isIDStart()

版本：php7

(PHP 7)

Check if code point is permissible as the first character in an identifier

说明

publicstaticIntlChar::isIDStart(mixed $codepoint): bool

Determines if the specified character is permissible as the first character in an identifier according to Unicode(The Unicode Standard, Version 3.0, chapter 5.16 Identifiers).

TRUE for characters with general categories "L"(letters)and "Nl"(letter numbers).

参数

$codepoint

The integer codepoint value(e.g.0x2603forU+2603 SNOWMAN), or the character encoded as a UTF-8 string(e.g."u{2603}")

返回值

Returns TRUE if$codepointmay start an identifier,FALSE if not.

范例

Testing different code points

<?php
var_dump(IntlChar::isIDStart("A"));
var_dump(IntlChar::isIDStart("$"));
var_dump(IntlChar::isIDStart("\n"));
var_dump(IntlChar::isIDStart("\u{2603}"));
?>

以上例程会输出：

bool(true)
bool(false)
bool(false)
bool(false)

参见

• IntlChar::isalpha() Check if code point is a letter character
• IntlChar::isIDPart() Check if code point is permissible in an identifier
• IntlChar::PROPERTY_ID_START