in progressIn fact, PHP string is a character array. Suppose we define a string
<ol class="dp-xml"><li class="alt"><span><span class="tag"><strong><font color="#006699"><?</FONT></STRONG></SPAN><SPAN> </SPAN></SPAN><LI class=""><SPAN> </SPAN><LI class=alt><SPAN>$</SPAN><SPAN class=attribute><FONT color=#ff0000>string</FONT></SPAN><SPAN> =</SPAN><SPAN class=attribute-value><FONT color=#0000ff>"hello world"</FONT></SPAN><SPAN>; </SPAN></SPAN><LI class=""><SPAN> </SPAN><LI class=alt><SPAN>/* </SPAN><LI class=""><SPAN> </SPAN><LI class=alt><SPAN>这个PHP字符串是由 h , e , l , l , o , 空格 , w ,o,r,l,d 这几个字符组成 至于是以什么结尾的我现在能了解, 可能需要查看PHP原代码才能发掘 </SPAN><LI class=""><SPAN> </SPAN><LI class=alt><SPAN>*/ </SPAN><LI class=""><SPAN> </SPAN><LI class=alt><SPAN>//那我以上所说的有什么根据呢?下面可以测试 </SPAN><LI class=""><SPAN> </SPAN><LI class=alt><SPAN>echo $string[2];//显示出第3个字符 l ,我们可以尝试改变 </SPAN><LI class=""><SPAN> </SPAN><LI class=alt><SPAN>$string[2]="A";//更改其中的 一个字符; </SPAN><LI class=""><SPAN> </SPAN><LI class=alt><SPAN>echo $string;// 得到 heAlo world </SPAN><LI class=""><SPAN> </SPAN><LI class=alt><SPAN>//那么我们可以尝试为 $string[2] 更改为字符串 </SPAN><LI class=""><SPAN> </SPAN><LI class=alt><SPAN>$string[2]="AAAAAA";//测试 看看PHP会不会把 其后面的字符覆盖 </SPAN><LI class=""><SPAN> </SPAN><LI class=alt><SPAN>echo $string;// 得到 heAlo world ,呵呵 看来PHP做了安全处理 </SPAN><LI class=""><SPAN> </SPAN><LI class=alt><SPAN></SPAN><SPAN class=tag><STRONG><FONT color=#006699>?></font></strong></span><span> </span></span></li></ol>
Hope everyone can pass The above code completely understands the composition principle of PHP strings.