PHP study notes: Enter a sentence and output the words in reverse order

Convention: Sentences use spaces as word separators and periods as end symbols.

Implementation ideas:

Use the function explode(separator, string, limit) to split the string, and then split and cut off the symbol from the last member of the obtained data. Use a new array to receive the string in reverse order and add periods.

Code implementation:

<?php <br />/**<br> * Created by PhpStorm.<br> * User: Administrator<br> * Date: 2016/9/25 0025<br> * Time: 22:29<br> */<br>//需要被倒序的字符串<br>$str="I am a handsome boy.";<br>$str_len=strlen($str);<br>//echo $str_len;输出结果为20，确认没问题。<br>//截取.号之前的字符substr(string,start,length)<br>$str=substr($str,0,$str_len-1);<br>//echo $str;得出I am a handsome boy，语句没问题<br>//转为数组<br>$str_arr=explode(' ',$str);<br>//var_dump($str_arr);结果无误<br>//倒序接收<br>$str_str_new=array_reverse($str_arr);<br>//数组转为字符串<br>$str_str_new_str=implode(' ',$str_str_new);<br>echo '转换前：'.$str."<br>".'转换后：'.$str_str_new_str.'.';

Effect: