is_string
変数が文字列であるかどうかを検出します
日本語
日本語
检查变量是否为字符串类型：
<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 string double-quoted-string">"hello"</span> <span class="token punctuation">;</span> <span class="token keyword">エコー</span><span class="token string double-quoted-string">「a is」</span> <span class="token operator">。</span> <span class="token punctuation">（</span> <span class="token function">is_string</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 single-quoted-string">'a string'</span> <span class="token punctuation">：</span> <span class="token string single-quoted-string">'not a string'</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">エコー</span><span class="token string double-quoted-string">「b is」</span> <span class="token operator">。</span> <span class="token punctuation">（</span> <span class="token function">is_string</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 single-quoted-string">'a string'</span> <span class="token punctuation">：</span> <span class="token string single-quoted-string">'not a string'</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</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 punctuation">（</span> <span class="token function">is_string</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 single-quoted-string">'a string'</span> <span class="token punctuation">：</span> <span class="token string single-quoted-string">'"not a string'</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 punctuation">（</span> <span class="token function">is_string</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 single-quoted-string">'a string'</span> <span class="token punctuation">：</span> <span class="token string single-quoted-string">'"not a string'</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 punctuation">（</span> <span class="token function">is_string</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 single-quoted-string">'a string'</span> <span class="token punctuation">：</span> <span class="token string single-quoted-string">'"not a string'</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 punctuation">（</span> <span class="token function">is_string</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 single-quoted-string">'a string'</span> <span class="token punctuation">：</span> <span class="token string single-quoted-string">'not a string'</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 string double-quoted-string">""</span> <span class="token punctuation">;</span> <span class="token keyword">echo</span> <span class="token string double-quoted-string">"g is"</span> <span class="token operator">。</span> <span class="token punctuation">（</span> <span class="token function">is_string</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 single-quoted-string">'a string'</span> <span class="token punctuation">：</span> <span class="token string single-quoted-string">'"not a string'</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>
doubleval
is_integer
is_int
is_null
is_float
is_string
is_bool
is_resource
