20 秒をかけて、PHP の基本的な知識ポイントをいくつか覚えてください。

20 秒を使って、いくつかの基本的な PHP 知識ポイントを覚えてください。

配列:
インデックス付き配列: 配列のキーは、0 から始まる整数の配列です。
連想配列: 配列のキーは文字列の配列です

<code class=" hljs php"><span class="hljs-comment">//索引数组</span><span class="hljs-variable">$arr</span>=<span class="hljs-keyword">array</span>(<span class="hljs-string">'I'</span>,<span class="hljs-string">'love'</span>,<span class="hljs-string">'you'</span>);<span class="hljs-comment">//关联数组</span><span class="hljs-variable">$arr0</span>=<span class="hljs-keyword">array</span>(<span class="hljs-string">'apple'</span>=><span class="hljs-string">"苹果"</span>,<span class="hljs-string">'yellow'</span>=><span class="hljs-string">"黄色"</span>);</code>

foreach で配列を走査します

<code class=" hljs php"><span class="hljs-comment">//数组的遍历</span><span class="hljs-variable">$arr</span>=<span class="hljs-keyword">array</span>(<span class="hljs-string">"苹果"</span>,<span class="hljs-string">"黄色"</span>);<span class="hljs-keyword">foreach</span>(<span class="hljs-variable">$arr</span> <span class="hljs-keyword">as</span> <span class="hljs-variable">$key</span>=><span class="hljs-variable">$value</span>){    <span class="hljs-keyword">echo</span> <span class="hljs-string">'<br>键是:'</span>.<span class="hljs-variable">$key</span>.<span class="hljs-string">'对应的值是:'</span>.<span class="hljs-variable">$value</span>;      }<span class="hljs-variable">$arr0</span>=<span class="hljs-keyword">array</span>(<span class="hljs-string">'apple'</span>=><span class="hljs-string">"苹果"</span>,<span class="hljs-string">'yellow'</span>=><span class="hljs-string">"黄色"</span>);<span class="hljs-keyword">foreach</span>(<span class="hljs-variable">$arr0</span> <span class="hljs-keyword">as</span> <span class="hljs-variable">$key</span>=><span class="hljs-variable">$value</span>){    <span class="hljs-keyword">echo</span> <span class="hljs-string">'<br>键是：'</span>.<span class="hljs-variable">$key</span>.<span class="hljs-string">'，对应的值是：'</span>.<span class="hljs-variable">$value</span>;}</code>

関数が存在するかどうかを判断します: function_exsits (関数名)

<code class=" hljs php"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">sayHello</span><span class="hljs-params">()</span>{</span>    <span class="hljs-keyword">echo</span> <span class="hljs-string">'hello'</span>;}<span class="hljs-variable">$test</span>=<span class="hljs-string">'sayHello'</span>;<span class="hljs-keyword">if</span>(function_exsits(<span class="hljs-variable">$test</span>)){    sayHello();}<span class="hljs-comment">//输出hello</span></code>

コンストラクター: オブジェクトの作成時に呼び出されるメソッド
デストラクター: オブジェクトの破棄時に呼び出されるメソッド

<code class=" hljs cs">class Car(){    <span class="hljs-keyword">public</span> __<span class="hljs-title">construct</span>(){        echo <span class="hljs-string">'对象已经创建'</span>;    }    <span class="hljs-keyword">public</span> __<span class="hljs-title">destruct</span>(){        echo <span class="hljs-string">'对象已经销毁'</span>;    }}$car=<span class="hljs-keyword">new</span> Car();</code>

strpos: 文字列を検索するメソッド

<code class=" hljs php"><span class="hljs-variable">$str</span>=<span class="hljs-string">'hello world'</span>;<span class="hljs-keyword">echo</span> strpos(<span class="hljs-variable">$str</span>,<span class="hljs-string">'world'</span>);<span class="hljs-comment">//输出6，从第6位开始</span></code>

implode: 戻り値: 配列要素を文字列に結合します

<code class=" hljs php"><span class="hljs-variable">$arr</span> = <span class="hljs-keyword">array</span>(<span class="hljs-string">'abc'</span>, <span class="hljs-string">'defg'</span>);<span class="hljs-variable">$arr0</span> = implode(<span class="hljs-string">''</span>, <span class="hljs-variable">$arr</span>);print_r(<span class="hljs-variable">$arr0</span>);<span class="hljs-comment">//结果显示abcdefg</span></code>

explode: 戻り値: この関数は文字列で構成される配列を返します

<code class=" hljs ruby"><span class="hljs-variable">$str</span>=<span class="hljs-string">"abc,defg"</span>;<span class="hljs-variable">$arr</span>=explode(<span class="hljs-string">','</span>,<span class="hljs-variable">$str</span>);print_r(<span class="hljs-variable">$arr</span>); <span class="hljs-regexp">//</span>结果返回一个数组,里面有两个元素<span class="hljs-symbol">:</span> abc和defg</code>

この記事の著者: 著者: Luo Jianyuan http://blog.csdn.net/sunyuan_software