log10
以 10 为底的对数
在本例中,我们对不同的数应用 log10()
函数:
<span class="token php language-php"><span class="token delimiter important"><?php</span> <span class="token keyword">echo</span><span class="token punctuation">(</span><span class="token function">log10</span><span class="token punctuation">(</span><span class="token number">2.7183</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">echo</span><span class="token punctuation">(</span><span class="token function">log10</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 punctuation">;</span> <span class="token keyword">echo</span><span class="token punctuation">(</span><span class="token function">log10</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">echo</span><span class="token punctuation">(</span><span class="token function">log10</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 punctuation">;</span> <span class="token keyword">echo</span><span class="token punctuation">(</span><span class="token function">log10</span><span class="token punctuation">(</span><span class="token operator">-</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token delimiter important">?></span></span>