gettype

实例

返回不同变量的类型：

<span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token variable">$a</span> <span class="token operator">=</span> <span class="token number">3</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token function">gettype</span><span class="token punctuation">(</span><span class="token variable">$a</span><span class="token punctuation">)</span> <span class="token operator">.</span> <span class="token string double-quoted-string">"<br>"</span><span class="token punctuation">;</span>

<span class="token variable">$b</span> <span class="token operator">=</span> <span class="token number">3.2</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token function">gettype</span><span class="token punctuation">(</span><span class="token variable">$b</span><span class="token punctuation">)</span> <span class="token operator">.</span> <span class="token string double-quoted-string">"<br>"</span><span class="token punctuation">;</span>

<span class="token variable">$c</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"Hello"</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token function">gettype</span><span class="token punctuation">(</span><span class="token variable">$c</span><span class="token punctuation">)</span> <span class="token operator">.</span> <span class="token string double-quoted-string">"<br>"</span><span class="token punctuation">;</span>

<span class="token variable">$d</span> <span class="token operator">=</span> <span class="token keyword">array</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token function">gettype</span><span class="token punctuation">(</span><span class="token variable">$d</span><span class="token punctuation">)</span> <span class="token operator">.</span> <span class="token string double-quoted-string">"<br>"</span><span class="token punctuation">;</span>

<span class="token variable">$e</span> <span class="token operator">=</span> <span class="token keyword">array</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"red"</span><span class="token punctuation">,</span> <span class="token string double-quoted-string">"green"</span><span class="token punctuation">,</span> <span class="token string double-quoted-string">"blue"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token function">gettype</span><span class="token punctuation">(</span><span class="token variable">$e</span><span class="token punctuation">)</span> <span class="token operator">.</span> <span class="token string double-quoted-string">"<br>"</span><span class="token punctuation">;</span>

<span class="token variable">$f</span> <span class="token operator">=</span> <span class="token constant">NULL</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token function">gettype</span><span class="token punctuation">(</span><span class="token variable">$f</span><span class="token punctuation">)</span> <span class="token operator">.</span> <span class="token string double-quoted-string">"<br>"</span><span class="token punctuation">;</span>

<span class="token variable">$g</span> <span class="token operator">=</span> <span class="token constant boolean">false</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token function">gettype</span><span class="token punctuation">(</span><span class="token variable">$g</span><span class="token punctuation">)</span> <span class="token operator">.</span> <span class="token string double-quoted-string">"<br>"</span><span class="token punctuation">;</span>
<span class="token delimiter important">?></span></span>

亲自试一试

例子解释：

gettype() 函数用于检查不同类型的变量（整数、浮点数、字符串、数组、空值和布尔值）并返回它们的类型。例如，对于整数变量 $a，gettype($a) 将返回字符串 "integer"。对于浮点数变量 $b，它将返回 "double"，对于字符串变量 $c，它将返回 "string"，依此类推。如果变量是关闭的资源，在 PHP 7.2 及更高版本中，gettype() 将返回 "resource (closed)"，而在早期版本中，它可能返回 "unknown type"。