substr_count

Beispiel

Beispiel 1

Berechnen Sie die Häufigkeit, in der "Shanghai" in einer Zeichenfolge erscheint:

 <span class="token php language-php"><span class="token delimiter important"><? Php</span>
<span class="token keyword">echo</span> <span class="token function">substr_count</span> <span class="token punctuation">(</span> <span class="token string double-quoted-string">"Ich liebe Shanghai. Shanghai ist die größte Stadt in China."</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"Shanghai"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token delimiter important">?></span></span>

Probieren Sie es selbst aus

Beispiel 2

Verwenden Sie alle Parameter:

 <span class="token php language-php"><span class="token delimiter important"><? Php</span>
<span class="token variable">$ str</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"Das ist schön"</span> <span class="token punctuation">;</span>
<span class="token keyword">Echo</span> <span class="token function">Strlen</span> <span class="token punctuation">(</span> <span class="token variable">$ str</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 comment">// Verwenden Sie Strlen (), um die Stringlänge zurückzugeben</span>
<span class="token keyword">echo</span> <span class="token function">substr_count</span> <span class="token punctuation">(</span> <span class="token variable">$ str</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"ist"</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 comment">// Häufigkeit "ist" wird in der Zeichenfolge angezeigt</span>
<span class="token keyword">echo</span> <span class="token function">substr_count</span> <span class="token punctuation">(</span> <span class="token variable">$ str</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"ist"</span> <span class="token punctuation">,</span> <span class="token number">2</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 comment">// Die Zeichenfolge ist auf "IS is schön" reduziert.</span>
<span class="token keyword">echo</span> <span class="token function">substr_count</span> <span class="token punctuation">(</span> <span class="token variable">$ str</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"ist"</span> <span class="token punctuation">,</span> <span class="token number">3</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 comment">// Die Zeichenfolge ist auf "S ist schön" reduziert.</span>
<span class="token keyword">echo</span> <span class="token function">substr_count</span> <span class="token punctuation">(</span> <span class="token variable">$ str</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"ist"</span> <span class="token punctuation">,</span> <span class="token number">3</span> <span class="token punctuation">,</span> <span class="token number">3</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 comment">// Die Zeichenfolge ist auf "Si" reduziert.</span>
<span class="token delimiter important">?></span></span>

Probieren Sie es selbst aus

Beispiel 3

Überlappende Substrings:

 <span class="token php language-php"><span class="token delimiter important"><? Php</span>
<span class="token variable">$ str</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"abcabcab"</span> <span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token function">substr_count</span> <span class="token punctuation">(</span> <span class="token variable">$ str</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"abcab"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// Diese Funktion zählt keine überlappenden Substrings nicht</span>
<span class="token delimiter important">?></span></span>

Probieren Sie es selbst aus

Beispiel 4

Wenn die Start- und Längenparameter die Zeichenfolgelänge überschreiten, gibt die Funktion eine Warnung aus:

 <span class="token php language-php"><span class="token delimiter important"><? Php</span>
<span class="token keyword">echo</span> <span class="token variable">$ str</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"Das ist schön"</span> <span class="token punctuation">;</span>
<span class="token function">substr_count</span> <span class="token punctuation">(</span> <span class="token variable">$ str</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"ist"</span> <span class="token punctuation">,</span> <span class="token number">3</span> <span class="token punctuation">,</span> <span class="token number">9</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token delimiter important">?></span></span>

Da der Längenwert die Länge der Zeichenfolge überschreitet (3 + 9 ist größer als 12), wird eine Warnung mit ihm ausgegeben.