empty
변수가 비어 있는지 확인하십시오
변수가 비어 있는지 확인합니다. 또한 변수가 설정/선언되었는지 확인하십시오.
<span class="token php language-php"><span class="token delimiter important"><? php</span>
<span class="token variable">$ a</span> <span class="token operator">=</span> <span class="token number">0</span> <span class="token punctuation">;</span>
<span class="token comment">// $ a가 비어 있기 때문에 결과는 참입니다</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span> <span class="token keyword">빈</span> <span class="token punctuation">(</span> <span class="token variable">$ a</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 string double-quoted-string">"variable 'a'는 비어 있습니다. <br>"</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token comment">// $ a가 설정되어 있기 때문에 결과는 참입니다</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span> <span class="token keyword">isset</span> <span class="token punctuation">(</span> <span class="token variable">$ a</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">에코</span> <span class="token string double-quoted-string">"변수 'a'가 설정되었습니다</span> <span class="token punctuation">.</span>
<span class="token punctuation">}</span>
<span class="token delimiter important">?></span></span>