PHP字符串word末字符实现大小写互换的方法

2015-01-24信息快讯网

这篇文章主要介绍了PHP字符串word末字符实现大小写互换的方法,是涉及PHP字符串转换非常实用的技巧,需要的朋友可以参考下

本文实例讲述了PHP字符串word末字符实现大小写互换的方法。分享给大家供大家参考。具体实现方法如下:

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:

<?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:

<?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:

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"

希望本文所述对大家的PHP程序设计有所帮助。

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