lcfirst

(PHP 5 >= 5.3.0, PHP 7, PHP 8)

lcfirst使一个字符串的第一个字符小写

说明

lcfirst ( string $str ) : string

返回第一个字母小写的 str ,如果是字母的话。

需要注意的是"字母"是由当前语言区域决定的。比如,在默认的"C"区域像日耳曼语系中的元音变音a (?) 将不会被转换。

参数

str

输入的字符串。

返回值

返回转换后的字符串。

范例

Example #1 lcfirst() 例子:

<?php
$foo 
'HelloWorld';
$foo lcfirst($foo);             // helloWorld

$bar 'HELLO WORLD!';
$bar lcfirst($bar);             // hELLO WORLD!
$bar lcfirst(strtoupper($bar)); // hELLO WORLD!
?>

参见

User Contributed Notes

phpnet at katylavallee dot com 02-Apr-2009 08:50
Easiest work-around I've found for <5.3:
<?php

$string
= "CamelCase"
$string{0} = strtolower($string{0})
echo
$string; // outputs camelCase

?>
ahlers_wim at hotmail dot com 22-Nov-2008 09:48
As of PHP release 6 direct reference modification is not permitted any more.
Reference modification is the process of manipulating characters within a string by means of the instruction such as:
$str[0] in the code line: $str[0] = strtolower($str[0]);

For this reason I have recoded the lcfirst function (on function_exists('lcfirst') === false) as follows:

<?php
if ( false === function_exists('lcfirst') ):
    function
lcfirst( $str )
    { return (string)(
strtolower(substr($str,0,1)).substr($str,1));}
endif;
?>

Remarks:
Also notice that I have used the more modern scope delimeters (if:-endif;) and I have also removed the unnecessary intermediate result. That is, the manipulation is returned directly.
alex aulbach 06-Oct-2008 09:20
In some cases maybe more useful?

 $lower = strtolower( substr($upper,0,1) ) . substr($upper,1);
harmor 05-May-2008 03:43
A slight modification from Northie's post here ( http://us2.php.net/manual/en/function.ucfirst.php#68443), where lcfirst may not exist in your PHP build:

<?php

if(false === function_exists('lcfirst'))
{
   
/**
     * Make a string's first character lowercase
     *
     * @param string $str
     * @return string the resulting string.
     */
   
function lcfirst( $str ) {
       
$str[0] = strtolower($str[0]);
        return (string)
$str;
    }
}

/* Tests */
echo var_dump(lcFirst(NULL)).'<br />';    /* string(0) ""  */
echo var_dump(lcFirst(''))  .'<br />';    /* string(0) ""  */
echo var_dump(lcFirst('S')) .'<br />';    /* string(1) "S" */
echo var_dump(lcFirst('é')) .'<br />';    /* string(0) "?" */
echo var_dump(lcFirst('Hello World!!!')); /* string(14) "hello World!!!"  */
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