IntlChar::isdefined()

版本：php7

(PHP 7)

Check whether the code point is defined

说明

Determines whether the specified code point is "defined", which usually means that it is assigned a character.

TRUEfor general categories other than "Cn"(other, not assigned).

Note that non-character code points(e.g., U+FDD0)are not "defined"(they are Cn), but surrogate code points are "defined"(Cs).

参数

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

ReturnsTRUEif$codepointis a defined character,FALSEif not.

范例

Testing different code points

以上例程会输出：

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

参见

• IntlChar::isdigit() Check if code point is a digit character
• IntlChar::isalpha() Check if code point is a letter character
• IntlChar::isalnum() Check if code point is an alphanumeric character
• IntlChar::isupper() Check if code point has the general category "Lu"(uppercase letter)
• IntlChar::islower() Check if code point is a lowercase letter
• IntlChar::istitle() Check if code point is a titlecase letter