is_integer

实例

检查变量是否为整数类型：

<span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token variable">$a</span> <span class="token operator">=</span> <span class="token number">32</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token string double-quoted-string">"a is "</span> <span class="token operator">.</span> <span class="token function">is_integer</span><span class="token punctuation">(</span><span class="token variable">$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">$b</span> <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token string double-quoted-string">"b is "</span> <span class="token operator">.</span> <span class="token function">is_integer</span><span class="token punctuation">(</span><span class="token variable">$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">$c</span> <span class="token operator">=</span> <span class="token number">32.5</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token string double-quoted-string">"c is "</span> <span class="token operator">.</span> <span class="token function">is_integer</span><span class="token punctuation">(</span><span class="token variable">$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">$d</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"32"</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token string double-quoted-string">"d is "</span> <span class="token operator">.</span> <span class="token function">is_integer</span><span class="token punctuation">(</span><span class="token variable">$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">$e</span> <span class="token operator">=</span> <span class="token constant boolean">true</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token string double-quoted-string">"e is "</span> <span class="token operator">.</span> <span class="token function">is_integer</span><span class="token punctuation">(</span><span class="token variable">$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">$f</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"null"</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token string double-quoted-string">"f is "</span> <span class="token operator">.</span> <span class="token function">is_integer</span><span class="token punctuation">(</span><span class="token variable">$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 delimiter important">?></span></span>

亲自试一试

例子解释：

在 PHP 中，布尔值 true 和字符串 "32" 都不是整数类型，即使字符串包含数字也是如此。所以，对于 $d 和 $e 的检查将返回 FALSE。同样地，$f 是一个字符串，尽管它的内容是 "null"，但它也不是整数类型，所以检查也会返回 FALSE。而浮点数如 $c 显然也不是整数，因此 is_int($c) 同样会返回 FALSE。