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：复制代码 代码如下: php function convertLastChar($str) { $markArr = array(", ", "' ", "/" ", ". ", "; "); $ret = ""; for ($i = 0, $j = strlen($str); $i $i++) { if ($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. Asource: 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 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"希望本文所述对大家的PHP程序设计有所帮助。PHP教程
