使用PHP怎么对字符串的word末字符的大小写进行转换？相信很多没有经验的人对此束手无策，为此本文总结了问题出现的原因和解决方法，通过这篇文章希望你能解决这个问题。
一、要求：
给出一个字符串如 “A journey of, a thousand 'miles' must can't \"begin\" with a single step.” ，通过 PHP 程序处理变成 “a journeY oF, A thousanD 'mileS' musT can'T "begiN" witH A singlE steP.”
这里需要注意：
1、每个单词最后的字符如果是大写就变成小写，如果是小写就变成大写。
2、需要考虑类似 can't 这种形式的转换。
3、标点符号（只考虑 , ' " . ;）不用变化。
二、参考算法如下：
复制代码 代码如下:
<?php
function convertLastChar($str) {
$markArr = array(", ", "' ", "\" ", ". ", "; ");
$ret = "";
for ($i = 0, $j = strlen($str); $i < $j; $i++) {
if ($i < $j - 2) {
$afterStr = $str{$i + 1} . $str{$i + 2};
} else if ($i < $j - 1) {
$afterStr = $str{$i + 1} . " ";
}
if (in_array($afterStr, $markArr)
|| $i == $j - 1
|| $str{$i + 1} == " ") {
$ret .= strtoupper($str{$i}) === $str{$i}
? strtolower($str{$i})
: strtoupper($str{$i});
} else {
$ret .= $str{$i};
}
}
return $ret;
}
?>
测试代码如下：
复制代码 代码如下:
<?php
//test
$str1 = "A journey of, a thousand 'miles' must can't \"begin\" with a single step.";
$str2 = "A journey of, a thousand 'miles' must can't \"begin\" with a single step. ";
$str3 = "A journey of, a thousand 'miles' must can't \"begin\" with a single step. a ";
$str4 = "A journey of, a thousand 'miles' must can't \"begin\" with a single step. a B";
$str5 = "A journey of, a thousand 'miles' must can't \"begin\" with a single step. a b'";
$str6 = "A journey of, a thousand 'miles' must can't \"begin\" with a single step. a B\"";
echo "source:<br/>" . $str1 . "<br/>result:<br/>" . convertLastChar($str1) . "<br/><br/>";
echo "source:<br/>" . $str2 . "<br/>result:<br/>" . convertLastChar($str2) . "<br/><br/>";
echo "source:<br/>" . $str3 . "<br/>result:<br/>" . convertLastChar($str3) . "<br/><br/>";
echo "source:<br/>" . $str4 . "<br/>result:<br/>" . convertLastChar($str4) . "<br/><br/>";
echo "source:<br/>" . $str5 . "<br/>result:<br/>" . convertLastChar($str5) . "<br/><br/>";
echo "source:<br/>" . $str6 . "<br/>result:<br/>" . convertLastChar($str6) . "<br/><br/>";
?>
运行结果如下：
复制代码 代码如下:
source:
A journey of, a thousand 'miles' must can't "begin" with a single step.
result:
a journeY oF, A thousanD 'mileS' musT can'T "begiN" witH A singlE steP.
source:
A journey of, a thousand 'miles' must can't "begin" with a single step.
result:
a journeY oF, A thousanD 'mileS' musT can'T "begiN" witH A singlE steP.
source:
A journey of, a thousand 'miles' must can't "begin" with a single step. a
result:
a journeY oF, A thousanD 'mileS' musT can'T "begiN" witH A singlE steP. A
source:
A journey of, a thousand 'miles' must can't "begin" with a single step. a B
result:
a journeY oF, A thousanD 'mileS' musT can'T "begiN" witH A singlE steP. A b
source:
A journey of, a thousand 'miles' must can't "begin" with a single step. a b'
result:
a journeY oF, A thousanD 'mileS' musT can'T "begiN" witH A singlE steP. A B'
source:
A journey of, a thousand 'miles' must can't "begin" with a single step. a B"
result:
a journeY oF, A thousanD 'mileS' musT can'T "begiN" witH A singlE steP. A b"
看完上述内容，你们掌握使用PHP怎么对字符串的word末字符的大小写进行转换的方法了吗？如果还想学到更多技能或想了解更多相关内容，欢迎关注亿速云行业资讯频道，感谢各位的阅读！
免责声明：本站发布的内容（图片、视频和文字）以原创、转载和分享为主，文章观点不代表本网站立场，如果涉及侵权请联系站长邮箱：is@yisu.com进行举报，并提供相关证据，一经查实，将立刻删除涉嫌侵权内容。
