The
mb function is a function extension that processes text according to the encoding format.
Modify the /etc/php.ini configuration file and add extension=php_mbstring.so
Let’s use my most commonly used substr function as an example. It's clear at a glance.
Example:
<span style="color: #008080"> 1</span> <?<span style="color: #000000">php </span><span style="color: #008080"> 2</span> <span style="color: #008000">//</span><span style="color: #008000">phpinfo();</span> <span style="color: #008080"> 3</span> <span style="color: #800080">$str</span> = 'abcdef'<span style="color: #000000">; </span><span style="color: #008080"> 4</span> <span style="color: #0000ff">echo</span> <span style="color: #008080">strlen</span>(<span style="color: #800080">$str</span>);<span style="color: #008000">//</span><span style="color: #008000"> 6</span> <span style="color: #008080"> 5</span> <span style="color: #0000ff">echo</span> '<br/>'<span style="color: #000000">; </span><span style="color: #008080"> 6</span> <span style="color: #0000ff">echo</span> <span style="color: #008080">substr</span>(<span style="color: #800080">$str</span>, 1,2);<span style="color: #008000">//</span><span style="color: #008000"> bc</span> <span style="color: #008080"> 7</span> <span style="color: #0000ff">echo</span> '<br/>'<span style="color: #000000">; </span><span style="color: #008080"> 8</span> <span style="color: #008080"> 9</span> <span style="color: #800080">$str2</span> = '我是谁ab'<span style="color: #000000">; </span><span style="color: #008080">10</span> <span style="color: #0000ff">echo</span> <span style="color: #008080">substr</span>(<span style="color: #800080">$str2</span>, 2, 2);<span style="color: #008000">//</span><span style="color: #008000"> ��</span> <span style="color: #008080">11</span> <span style="color: #0000ff">echo</span> '<br/>'<span style="color: #000000">; </span><span style="color: #008080">12</span> <span style="color: #0000ff">echo</span> mb_substr(<span style="color: #800080">$str2</span>, 2, 2, 'UTF-8');<span style="color: #008000">//</span><span style="color: #008000"> 谁a</span> <span style="color: #008080">13</span> <span style="color: #0000ff">echo</span> '<br/>'<span style="color: #000000">; </span><span style="color: #008080">14</span> <span style="color: #0000ff">echo</span> <span style="color: #008080">strlen</span>(<span style="color: #800080">$str2</span>);<span style="color: #008000">//</span><span style="color: #008000"> 11</span> <span style="color: #008080">15</span> <span style="color: #0000ff">echo</span> '<br/>'<span style="color: #000000">; </span><span style="color: #008080">16</span> <span style="color: #0000ff">echo</span> mb_strlen(<span style="color: #800080">$str2</span>, 'UTF-8');<span style="color: #008000">//</span><span style="color: #008000"> 5</span> <span style="color: #008080">17</span> <span style="color: #0000ff">echo</span> '<br/>';
Look at lines 10 and 12, the effect is clear.