array_unshift
Insert one or more units at the beginning of an array
Insert the element "blue" into the array:
<span class="token php language-php"><span class="token delimiter important"><?php</span> <span class="token variable">$a</span> <span class="token operator">=</span> <span class="token keyword">array</span> <span class="token punctuation">(</span> <span class="token string double-quoted-string">"a"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"red"</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"b"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"green"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token function"></span></span><mark><span class="token function">array_unshift</span> <span class="token punctuation">(</span> <span class="token variable">$a</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"blue"</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">$a</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token delimiter important">?></span>
Show return value:
<span class="token php language-php"><span class="token delimiter important"><?php</span> <span class="token variable">$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">"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 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_unshift</span> <span class="token punctuation">(</span> <span class="token variable">$a</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"blue"</span> <span class="token punctuation">)</span></mark><span class="token punctuation"></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token delimiter important">?></span>
Use the numeric key name:
<span class="token php language-php"><span class="token delimiter important"><?php</span> <span class="token variable">$a</span> <span class="token operator">=</span> <span class="token keyword">array</span> <span class="token punctuation">(</span> <span class="token number">0</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"red"</span> <span class="token punctuation">,</span> <span class="token number">1</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"green"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token function"></span></span><mark><span class="token function">array_unshift</span> <span class="token punctuation">(</span> <span class="token variable">$a</span> <span class="token punctuation">,</span> <span class="token string double-quoted-string">"blue"</span> <span class="token punctuation">)</span></mark><span class="token punctuation"></span> <span class="token punctuation">;</span> <span class="token function">print_r</span> <span class="token punctuation">(</span> <span class="token variable">$a</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token delimiter important">?></span>