count_chars

實例

例子1

返回一個字符串，包含所有在"Hello World!" 中使用過的不同字符（模式3）：

 <span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token variable">$str</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"Hello World!"</span> <span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token function">count_chars</span> <span class="token punctuation">(</span> <span class="token variable">$str</span> <span class="token punctuation">,</span> <span class="token number">3</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token delimiter important">?></span></span>

親自試一試

例子2

返回一個字符串，包含所有在"Hello World!" 中未使用過的字符（模式4）：

 <span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token variable">$str</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"Hello World!"</span> <span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token function">count_chars</span> <span class="token punctuation">(</span> <span class="token variable">$str</span> <span class="token punctuation">,</span> <span class="token number">4</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token delimiter important">?></span></span>

親自試一試

例子3

在此實例中，我們將使用count_chars() 來檢查字符串，返回模式設置為1。模式1 將返回一個數組，ASCII 值為鍵名，出現的次數為鍵值：

 <span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token variable">$str</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"Hello World!"</span> <span class="token punctuation">;</span>
<span class="token function">print_r</span> <span class="token punctuation">(</span> <span class="token function">count_chars</span> <span class="token punctuation">(</span> <span class="token variable">$str</span> <span class="token punctuation">,</span> <span class="token number">1</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token delimiter important">?></span></span>

親自試一試

例子4

統計某個ASCII 字符在字符串中出現次數的另一個實例：

 <span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token variable">$str</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"PHP is pretty fun!!"</span> <span class="token punctuation">;</span>
<span class="token variable">$strArray</span> <span class="token operator">=</span> <span class="token function">count_chars</span> <span class="token punctuation">(</span> <span class="token variable">$str</span> <span class="token punctuation">,</span> <span class="token number">1</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

<span class="token keyword">foreach</span> <span class="token punctuation">(</span> <span class="token variable">$strArray</span> <span class="token keyword">as</span> <span class="token variable">$key</span> <span class="token operator">=></span> <span class="token variable">$value</span> <span class="token punctuation">)</span>
  <span class="token punctuation">{</span>
<span class="token keyword">echo</span> <span class="token string double-quoted-string">"字符<b>&#39;"</span> <span class="token operator">.</span> <span class="token function">chr</span> <span class="token punctuation">(</span> <span class="token variable">$key</span> <span class="token punctuation">)</span> <span class="token operator">.</span> <span class="token string double-quoted-string">"&#39;</b> 被找到<span class="token interpolation"><span class="token variable">$value</span></span>次。<br>"</span> <span class="token punctuation">;</span>
  <span class="token punctuation">}</span>
<span class="token delimiter important">?></span></span>

親自試一試