unset
釋放給定的變量
中文(繁體)
中文(繁體)
銷毀變量：
<span class="token php language-php"><span class="token delimiter important"><?php</span> <span class="token variable">$a</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"Hello world!"</span> <span class="token punctuation">;</span> <span class="token keyword">echo</span> <span class="token string double-quoted-string">"刪除前變量'a' 的值："</span> <span class="token operator">.</span> <span class="token variable">$a</span> <span class="token operator">.</span> <span class="token string double-quoted-string">"<br>"</span> <span class="token punctuation">;</span> <span class="token keyword">unset</span> <span class="token punctuation">(</span> <span class="token variable">$a</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token keyword">echo</span> <span class="token string double-quoted-string">"刪除後變量'a' 的值："</span> <span class="token operator">.</span> <span class="token variable">$a</span> <span class="token punctuation">;</span> <span class="token delimiter important">?></span></span>
is_iterable
is_callable
get_resource_id
var_dump
is_float
is_countable
doubleval
is_double
