substr_compare
二进制安全比较字符串(从偏移位置比较指定长度)
比较两个字符串:
<span class="token php language-php"><span class="token delimiter important"><?php</span> <span class="token keyword">echo</span> <span class="token function">substr_compare</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">"Hello world"</span><span class="token punctuation">,</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token delimiter important">?></span></span>
比较两个字符串,当 string1 中供比较的开始位置为 6 时:
<span class="token php language-php"><span class="token delimiter important"><?php</span> <span class="token keyword">echo</span> <span class="token function">substr_compare</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">"world"</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 delimiter important">?></span></span>
使用所有的参数:
<span class="token php language-php"><span class="token delimiter important"><?php</span> <span class="token keyword">echo</span> <span class="token function">substr_compare</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"world"</span><span class="token punctuation">,</span><span class="token string double-quoted-string">"or"</span><span class="token punctuation">,</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">echo</span> <span class="token function">substr_compare</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"world"</span><span class="token punctuation">,</span><span class="token string double-quoted-string">"ld"</span><span class="token punctuation">,</span><span class="token operator">-</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">echo</span> <span class="token function">substr_compare</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"world"</span><span class="token punctuation">,</span><span class="token string double-quoted-string">"orl"</span><span class="token punctuation">,</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">echo</span> <span class="token function">substr_compare</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"world"</span><span class="token punctuation">,</span><span class="token string double-quoted-string">"OR"</span><span class="token punctuation">,</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token constant boolean">TRUE</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">echo</span> <span class="token function">substr_compare</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"world"</span><span class="token punctuation">,</span><span class="token string double-quoted-string">"or"</span><span class="token punctuation">,</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">3</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">echo</span> <span class="token function">substr_compare</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"world"</span><span class="token punctuation">,</span><span class="token string double-quoted-string">"rl"</span><span class="token punctuation">,</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token delimiter important">?></span></span>
不同的返回值:
<span class="token php language-php"><span class="token delimiter important"><?php</span> <span class="token keyword">echo</span> <span class="token function">substr_compare</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">"Hello world!"</span><span class="token punctuation">,</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// 两字符串相等</span> <span class="token keyword">echo</span> <span class="token function">substr_compare</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">"Hello"</span><span class="token punctuation">,</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// <i>string1</i> 大于 <i>string2</i></span> <span class="token keyword">echo</span> <span class="token function">substr_compare</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">"Hello world! Hello!"</span><span class="token punctuation">,</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// <i>string1</i> 小于 <i>string2</i></span> <span class="token delimiter important">?></span></span>