PHP将字符转为大写的函数是哪个？

PHP将字符转为大写的函数是哪个？

在PHP中将字符转为大写的函数是“strtoupper()”，该函数的作用是将字符串转化为大写，语法为“strtoupper(string $string)”，返回值为转换后的大写字符串。

示例代码

<?php
$str = "Mary Had A Little Lamb and She LOVED It So";
$str = strtoupper($str);
echo $str; // 打印 MARY HAD A LITTLE LAMB AND SHE LOVED IT SO
?>

使用示例

<?php

define("LATIN1_UC_CHARS", "ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝ");
define("LATIN1_LC_CHARS", "àáâãäåæçèéêëìíîïðñòóôõöøùúûüý");

function uc_latin1 ($str) {
    $str = strtoupper(strtr($str, LATIN1_LC_CHARS, LATIN1_UC_CHARS));
    return strtr($str, array("ß" => "SS"));
}

?>

<?php

function strtoupper_utf8($string){
    $string=utf8_decode($string);
    $string=strtoupper($string);
    $string=utf8_encode($string);
    return $string;
}

?>