Check if code point is an ignorable character

# IntlChar::isIDIgnorable

(PHP 7, PHP 8)

IntlChar::isIDIgnorable — Check if code point is an ignorable character

### 说明

public static function IntlChar::isIDIgnorable(int|string `$codepoint`): ?bool

Determines if the specified character should be regarded as an ignorable character in an identifier.

`true` for characters with general category "Cf" (format controls) as well as non-whitespace ISO controls (U+0000..U+0008, U+000E..U+001B, U+007F..U+009F).

> 注意:

> Note that Unicode just recommends to ignore Cf (format controls).

### 参数

`codepoint`
  The int codepoint value (e.g. `0x2603` for U+2603 SNOWMAN), or the character encoded as a UTF-8 string (e.g. `"\u{2603}"`)

### 返回值

Returns `true` if `codepoint` is ignorable in identifiers, `false` if not. Returns `null` on failure.

### 示例

示例 #1 Testing different code points

    <?php
    var_dump(IntlChar::isIDIgnorable("A"));
    var_dump(IntlChar::isIDIgnorable(" "));
    var_dump(IntlChar::isIDIgnorable("\u{007F}"));
    ?>

以上示例会输出：

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

### 参见

- IntlChar::isIDStart() - Check if code point is permissible as the first character in an identifier
- IntlChar::isIDPart() - Check if code point is permissible in an identifier
- `IntlChar::PROPERTY_DEFAULT_IGNORABLE_CODE_POINT`

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