strcspn
获取不匹配遮罩的起始子字符串的长度
输出在字符串 "Hello world!" 中找到字符 "w" 之前查找的字符数:
<span class="token php language-php"><span class="token delimiter important"><?php</span> <span class="token keyword">echo</span> <span class="token function">strcspn</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"Hello world!"</span><span class="token punctuation">,</span><span class="token string double-quoted-string">"w"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token delimiter important">?></span></span>
使用所有的参数来输出在字符串 "Hello world!" 中找到字符 "w" 之前查找的字符数:
<span class="token php language-php"><span class="token delimiter important"><?php</span> <span class="token keyword">echo</span> <span class="token function">strcspn</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"Hello world!"</span><span class="token punctuation">,</span><span class="token string double-quoted-string">"w"</span><span class="token punctuation">,</span><span class="token number">0</span><span class="token punctuation">,</span><span class="token number">6</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// 开始位置是 0,搜索字符串的长度是 6。</span> <span class="token delimiter important">?></span></span>