# IntlChar::islower

(PHP 7, PHP 8)

IntlChar::islower — Check if code point is a lowercase letter

### 说明

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

Determines whether the specified code point has the general category "Ll" (lowercase letter).

> 注意:

> This misses some characters that are also lowercase but have a different general category value. In order to include those, use IntlChar::isULowercase().

### 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 an Ll lowercase letter, `false` if not. Returns `null` on failure.

### 示例

示例 #1 Testing different code points

`<?php
var_dump(IntlChar::islower("A"));
var_dump(IntlChar::islower("a"));
var_dump(IntlChar::islower("Φ"));
var_dump(IntlChar::islower("φ"));
var_dump(IntlChar::islower("1"));
?>`

以上示例会输出：

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

### 参见

- IntlChar::isupper() - Check if code point has the general category "Lu" (uppercase letter)
- IntlChar::istitle() - Check if code point is a titlecase letter
- IntlChar::tolower() - Make Unicode character lowercase
- IntlChar::toupper() - Make Unicode character uppercase
- `IntlChar::PROPERTY_LOWERCASE`
- ctype_lower() - 检测小写字符

`↑` and `↓` to navigate • `Enter` to select • `Esc` to close • `/` to open