array_keys

Beispiel

Beispiel 1

Gibt ein neues Array zurück, das alle Schlüsselnamen im Array enthält:

 <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 keyword">array</span> <span class="token punctuation">(</span> <span class="token string double-quoted-string">"volvo"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"xc90"</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"bmw"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"x5"</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"toyota"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"Highlander"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token function">print_r</span> <span class="token punctuation">(</span><span class="token function"></span></span><mark> <span class="token function">Array_keys</span> <span class="token punctuation">(</span> <span class="token variable">$ A</span> <span class="token punctuation">)</span></mark><span class="token punctuation"></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token delimiter important">?></span>

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Beispiel 2

Verwenden Sie den Wertparameter :

 <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 keyword">array</span> <span class="token punctuation">(</span> <span class="token string double-quoted-string">"volvo"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"xc90"</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"bmw"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"x5"</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"toyota"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"Highlander"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token function">print_r</span> <span class="token punctuation">(</span><span class="token function"></span></span><mark> <span class="token function">Array_keys</span> <span class="token punctuation">(</span> <span class="token variable">$ a</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"Highlander"</span> <span class="token punctuation">)</span></mark><span class="token punctuation"></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token delimiter important">?></span>

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Beispiel 3

Verwenden Sie strengen Parameter (Falsch):

 <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 keyword">Array</span> <span class="token punctuation">(</span> <span class="token number">10</span> <span class="token punctuation">,</span> <span class="token number">20</span> <span class="token punctuation">,</span> <span class="token number">30</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"10"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token function">print_r</span> <span class="token punctuation">(</span><span class="token function"></span></span><mark> <span class="token function">Array_keys</span> <span class="token punctuation">(</span> <span class="token variable">$ a</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"10"</span> <span class="token punctuation">,</span> <span class="token constant boolean">falsch</span> <span class="token punctuation">)</span></mark><span class="token punctuation"></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token delimiter important">?></span>

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Beispiel 4

Verwenden Sie den strengen Parameter (True):

 <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 keyword">Array</span> <span class="token punctuation">(</span> <span class="token number">10</span> <span class="token punctuation">,</span> <span class="token number">20</span> <span class="token punctuation">,</span> <span class="token number">30</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"10"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token function">print_r</span> <span class="token punctuation">(</span><span class="token function"></span></span><mark> <span class="token function">Array_keys</span> <span class="token punctuation">(</span> <span class="token variable">$ a</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"10"</span> <span class="token punctuation">,</span> <span class="token constant boolean">wahr</span> <span class="token punctuation">)</span></mark><span class="token punctuation"></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token delimiter important">?></span>

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