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<h1>Comment l'utiliser array_keys Évitez les erreurs en double dans les clés du tableau？PHP Des questions fréquemment posées au débutant</h1>
<p>exister PHP milieu，Les tableaux sont des structures de données très flexibles，Peut stocker les clés et les valeurs en même temps。Cependant，Un problème que les débutants rencontrent souvent：当你exister数组milieu不小心定义了重复的键，La valeur définie plus tard écrasera la valeur précédente，Provoque une perte de données ou des erreurs logiques。</p>
<h2>Situations communes de duplication des clés de tableau</h2>
<p>Donner un exemple simple：</p>
<pre><code </span><span><span class="hljs-class"><span class="hljs-keyword">class</span></span></span><span>="</span><span><span class="hljs-title">language</span></span><span>-</span><span><span class="hljs-title">php</span></span><span>">
$</span><span><span class="hljs-title">data</span></span><span> = [
"</span><span><span class="hljs-title">id</span></span><span>" => 1,
"</span><span><span class="hljs-title">name</span></span><span>" => "</span><span><span class="hljs-title">Alice</span></span><span>",
"</span><span><span class="hljs-title">id</span></span><span>" => 2
];
</span><span><span class="hljs-title">print_r</span></span><span>($</span><span><span class="hljs-title">data</span></span><span>);
</</span><span><span class="hljs-title">code</span></span><span>></</span><span><span class="hljs-title">pre</span></span><span>>
<</span><span><span class="hljs-title">p</span></span><span>>Après avoir coulé，数组milieu只会保留最后一次的 <</span><span><span class="hljs-title">code</span></span><span>>"</span><span><span class="hljs-title">id</span></span><span>" => 2</</span><span><span class="hljs-title">code</span></span><span>>，La première fois que je l'ai défini <</span><span><span class="hljs-title">code</span></span><span>>"</span><span><span class="hljs-title">id</span></span><span>" => 1</</span><span><span class="hljs-title">code</span></span><span>> A été couvert。</</span><span><span class="hljs-title">p</span></span><span>>
<</span><span><span class="hljs-title">h2</span></span><span>>Comment utiliser </span><span><span class="hljs-title">array_keys</span></span><span> Vérifiez la clé de répétition？</</span><span><span class="hljs-title">h2</span></span><span>>
<</span><span><span class="hljs-title">p</span></span><span>><</span><span><span class="hljs-title">code</span></span><span>></span><span><span class="hljs-title">array_keys</span></span><span>()</</span><span><span class="hljs-title">code</span></span><span>> 函数可以返回数组milieu所有键组成的新数组，Nous pouvons l'utiliser pour détecter s'il y a des clés en double。</</span><span><span class="hljs-title">p</span></span><span>>
<</span><span><span class="hljs-title">pre</span></span><span>><</span><span><span class="hljs-title">code</span></span><span> </span><span><span class="hljs-title">class</span></span><span>="</span><span><span class="hljs-title">language</span></span><span>-</span><span><span class="hljs-title">php</span></span><span>">
$</span><span><span class="hljs-title">data</span></span><span> = [
"</span><span><span class="hljs-title">id</span></span><span>" => 1,
"</span><span><span class="hljs-title">name</span></span><span>" => "</span><span><span class="hljs-title">Alice</span></span><span>",
"</span><span><span class="hljs-title">id</span></span><span>" => 2
];
$</span><span><span class="hljs-title">keys</span></span><span> = </span><span><span class="hljs-title">array_keys</span></span><span>($</span><span><span class="hljs-title">data</span></span><span>);
// Statistiques Le nombre d'occurrences de clés
$</span><span><span class="hljs-title">keyCounts</span></span><span> = </span><span><span class="hljs-title">array_count_values</span></span><span>($</span><span><span class="hljs-title">keys</span></span><span>);
// Trouver des clés en double
$</span><span><span class="hljs-title">duplicates</span></span><span> = </span><span><span class="hljs-title">array_filter</span></span><span>($</span><span><span class="hljs-title">keyCounts</span></span><span>, </span><span><span class="hljs-title">function</span></span><span>($</span><span><span class="hljs-title">count</span></span><span>) {
</span><span><span class="hljs-keyword">return</span></span><span> </span><span><span class="hljs-variable">$count</span></span><span> > </span><span><span class="hljs-number">1</span></span><span>;
});
</span><span><span class="hljs-keyword">if</span></span><span> (!</span><span><span class="hljs-keyword">empty</span></span><span>(</span><span><span class="hljs-variable">$duplicates</span></span><span>)) {
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"Découvrez les touches en double: "</span></span><span> . </span><span><span class="hljs-title function_ invoke__">implode</span></span><span>(</span><span><span class="hljs-string">", "</span></span><span>, </span><span><span class="hljs-title function_ invoke__">array_keys</span></span><span>(</span><span><span class="hljs-variable">$duplicates</span></span><span>));
} </span><span><span class="hljs-keyword">else</span></span><span> {
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"Aucune touche en double trouvée"</span></span><span>;
}
De cette façon, nous pouvons rapidement découvrir le problème des clés en double dans la logique du programme pour éviter les remplacements de données ultérieurs.
Les débutants PHP sont enclins à ignorer la superposition des touches de tableau, mais l'utilisation de fonctions telles que Array_Keys peut détecter et éviter les erreurs à l'avance pendant le processus de codage. Une bonne habitude consiste à garder la structure du tableau clair lors de la rédaction de code et de vérifier en cas de besoin, ce qui peut réduire considérablement le coût du débogage.
Étiquettes associées:
array_keys