expm1
返回 exp(number) - 1，甚至当 number 的值接近零也能计算出准确结果
简体中文
简体中文
在本例中，我们将对不同的数应用 expm1() 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">expm1</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">expm1</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 keyword">echo</span><span class="token punctuation">(</span><span class="token function">expm1</span><span class="token punctuation">(</span><span class="token number">5</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">expm1</span><span class="token punctuation">(</span><span class="token number">10</span><span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token delimiter important">?></span></span>
