<span><span><span class="hljs-meta"><?php</span></span><span>
</span><span><span class="hljs-comment">// 코드 의이 부분은 기사의 내용과 관련이 없습니다.</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"PHP 기사 예제가 시작됩니다<br>"</span></span><span>;
</span><span><span class="hljs-variable">$dummyArray</span></span><span> = [</span><span><span class="hljs-number">1</span></span><span>, </span><span><span class="hljs-number">2</span></span><span>, </span><span><span class="hljs-number">3</span></span><span>];
</span><span><span class="hljs-title function_ invoke__">print_r</span></span><span>(</span><span><span class="hljs-variable">$dummyArray</span></span><span>);
</span><span><span class="hljs-meta">?></span></span><span>
<hr>
</span><span><span class="hljs-meta"><?php</span></span><span>
<span class="hljs-comment">/*
제목: 사용 PHP ~의 array_key_first 맞잡다 array_values 怎么获取数组~의第一个值?자세한 분석
*/</span>
</span><span><span class="hljs-comment">// 존재하다 PHP 가운데,获取数组~의第一个值是一个常见需求。虽然可以直接使사용索引访问数值,但존재하다关联数组或键不连续~의数组가운데,我们需要더 안전합니다~의방법。PHP 제공 array_key_first 그리고 array_values 두 가지 기능,可以결합使사용来安全地获取数组~의第一个值。</span></span><span>
</span><span><span class="hljs-comment">// 예제 배열</span></span><span>
</span><span><span class="hljs-variable">$fruits</span></span><span> = [
</span><span><span class="hljs-string">'a'</span></span><span> => </span><span><span class="hljs-string">'사과'</span></span><span>,
</span><span><span class="hljs-string">'b'</span></span><span> => </span><span><span class="hljs-string">'바나나'</span></span><span>,
</span><span><span class="hljs-string">'c'</span></span><span> => </span><span><span class="hljs-string">'귤'</span></span><span>
];
</span><span><span class="hljs-comment">// 방법 1:使사용 array_values 获取数组~의值列表,첫 번째 요소를 가져 가십시오</span></span><span>
</span><span><span class="hljs-variable">$values</span></span><span> = </span><span><span class="hljs-title function_ invoke__">array_values</span></span><span>(</span><span><span class="hljs-variable">$fruits</span></span><span>);
</span><span><span class="hljs-variable">$firstValue1</span></span><span> = </span><span><span class="hljs-variable">$values</span></span><span>[</span><span><span class="hljs-number">0</span></span><span>];
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"방법 1获取~의第一个值: "</span></span><span> . </span><span><span class="hljs-variable">$firstValue1</span></span><span> . </span><span><span class="hljs-string">"<br>"</span></span><span>;
</span><span><span class="hljs-comment">// 방법 2:使사용 array_key_first 첫 번째 키를 얻으십시오,然后访问对应~의值</span></span><span>
</span><span><span class="hljs-variable">$firstKey</span></span><span> = </span><span><span class="hljs-title function_ invoke__">array_key_first</span></span><span>(</span><span><span class="hljs-variable">$fruits</span></span><span>);
</span><span><span class="hljs-variable">$firstValue2</span></span><span> = </span><span><span class="hljs-variable">$fruits</span></span><span>[</span><span><span class="hljs-variable">$firstKey</span></span><span>];
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"방법 2获取~의第一个值: "</span></span><span> . </span><span><span class="hljs-variable">$firstValue2</span></span><span> . </span><span><span class="hljs-string">"<br>"</span></span><span>;
</span><span><span class="hljs-comment">// 분석</span></span><span>
<span class="hljs-comment">/*
1. array_values($array) 会返回一个索引重置~의数组,값 만 유지됩니다,키 이름은 0 시작。
그러므로 $values[0] 永远是原数组~의第一个元素~의值。
2. array_key_first($array) 会返回数组가운데第一个元素~의键,배열 자체를 변경하지 마십시오。
결합 $array[$key] 就可以获取第一个元素~의值。这个방법존재하다键名不连续或不是数字索引时尤其可靠。
요약:
- 가치에만 관심이 있다면,可以사용 array_values 방법。
- 원래 키 이름을 보존하거나 연관 배열을 처리하려면,array_key_first 더 안전합니다。
- 两种방법都可以达到获取数组第一个值~의目~의,특정 선택은 실제 요구를 기반으로 할 수 있습니다。
*/</span>
</span><span><span class="hljs-meta">?></span></span><span>
</span></span>
관련 태그:
array_values