array_walk

Example

Example 1

Apply user-defined functions to each element in the array:

 <span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token keyword">function</span> <span class="token function-definition function">myfunction</span> <span class="token punctuation">(</span> <span class="token variable">$value</span> <span class="token punctuation">,</span> <span class="token variable">$key</span> <span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token keyword">echo</span> <span class="token string double-quoted-string">"The key <span class="token interpolation"><span class="token variable">$key</span></span> has the value <span class="token interpolation"><span class="token variable">$value</span></span> <br>"</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token variable">$a</span> <span class="token operator">=</span> <span class="token keyword">array</span> <span class="token punctuation">(</span> <span class="token string double-quoted-string">"a"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"red"</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"b"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"green"</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"c"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"blue"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token function"></span></span><mark><span class="token function">array_walk</span> <span class="token punctuation">(</span> <span class="token variable">$a</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"myfunction"</span> <span class="token punctuation">)</span></mark><span class="token punctuation"></span> <span class="token punctuation">;</span>
<span class="token delimiter important">?></span>

Try it yourself

Example 2

Set a parameter:

 <span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token keyword">function</span> <span class="token function-definition function">myfunction</span> <span class="token punctuation">(</span> <span class="token variable">$value</span> <span class="token punctuation">,</span> <span class="token variable">$key</span> <span class="token punctuation">,</span> <span class="token variable">$p</span> <span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token keyword">echo</span> <span class="token string double-quoted-string">" <span class="token interpolation"><span class="token variable">$key</span></span> <span class="token interpolation"><span class="token variable">$p</span></span> <span class="token interpolation"><span class="token variable">$value</span></span> <br>"</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token variable">$a</span> <span class="token operator">=</span> <span class="token keyword">array</span> <span class="token punctuation">(</span> <span class="token string double-quoted-string">"a"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"red"</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"b"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"green"</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"c"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"blue"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token function"></span></span><mark><span class="token function">array_walk</span> <span class="token punctuation">(</span> <span class="token variable">$a</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"myfunction"</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"has the value"</span> <span class="token punctuation">)</span></mark><span class="token punctuation"></span> <span class="token punctuation">;</span>
<span class="token delimiter important">?></span>

Try it yourself

Example 3

Change the value of an array element (note &$value):

 <span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token keyword">function</span> <span class="token function-definition function">myfunction</span> <span class="token punctuation">(</span> <span class="token operator">&</span> <span class="token variable">$value</span> <span class="token punctuation">,</span> <span class="token variable">$key</span> <span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token variable">$value</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"yellow"</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token variable">$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">"a"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"red"</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"b"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"green"</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"c"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"blue"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token function"></span></span><mark><span class="token function">array_walk</span> <span class="token punctuation">(</span> <span class="token variable">$a</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"myfunction"</span> <span class="token punctuation">)</span></mark><span class="token punctuation"></span> <span class="token punctuation">;</span>
<span class="token function">print_r</span> <span class="token punctuation">(</span> <span class="token variable">$a</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token delimiter important">?></span>

Try it yourself