php substr,iconv_substr,mb_substr

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<span> 2</span> <span><</span><span>head</span><span>><</span><span>meta </span><span>charset</span><span>='utf-8'</span><span>></span>
<span> 3</span> <span><</span><span>title</span><span>></span>截取中文字符串_脚本学堂_www.jbxue.com<span></</span><span>title</span><span>></span>
<span> 4</span> <span></</span><span>head</span><span>></span>
<span> 5</span> <span><</span><span>body</span><span>></span>
<span> 6</span> <span><?</span><span>php
</span><span> 7</span> <span>$str='123脚本学堂456欢迎大家的光临';
</span><span> 8</span> <span>echo substr($str,0,4);
</span><span> 9</span> <span>echo '<br>';
</span><span>10</span> <span>echo iconv_substr($str,0,4,'utf-8');
</span><span>11</span> <span>echo '<br>';
</span><span>12</span> <span>echo mb_substr($str,0,4,'utf-8');
</span><span>13</span> <span>?></span>
<span>14</span> <span></</span><span>body</span><span>></span>
<span>15</span> <span></</span><span>html</span><span>></span>