PHP字串word末字元大小寫互換，字串大小寫_PHP教程

PHP字串word末字元大小寫互換，字串大小寫

要求

給出一個字串如 “A journey of, a thousand 'miles' must can't \"begin\" with a single step.” ，通過 PHP 程式處理變成 “a journeY oF, A thousanD 'mileS' musT can'T "begiN" witH A singlE steP.”

注意：
1、每個單詞最後的字元如果是大寫就變成小寫，如果是小寫就變成大寫。
2、需要考慮類似 can't 這種形式的轉換。
3、標點符號（只考慮 , ' " . ;）不用變化。

參考演算法

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;    }?>

測試

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:
" . $str1 . "
result:
" . convertLastChar($str1) . "

";    echo "source:
" . $str2 . "
result:
" . convertLastChar($str2) . "

";    echo "source:
" . $str3 . "
result:
" . convertLastChar($str3) . "

";    echo "source:
" . $str4 . "
result:
" . convertLastChar($str4) . "

";    echo "source:
" . $str5 . "
result:
" . convertLastChar($str5) . "

";    echo "source:
" . $str6 . "
result:
" . convertLastChar($str6) . "

";?>

結果：

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 Bresult:a journeY oF, A thousanD 'mileS' musT can'T "begiN" witH A singlE steP. A bsource: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"

我們可以看到，是符合預期的。

題目來源

http://blog.sijiaomao.com/?p=98，有改動（增加了can't這種），按改後的規則，原文答案全是錯的。

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